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ap-physics-course-description55 - PHYSICS PHYSICS B PHYSICS...

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Unformatted text preview: PHYSICS PHYSICS B PHYSICS C: MECHANICS PHYSICS C: ELECTRICITY AND MAGNETISM Course Description M AY 2 010, M AY 2 011 The College Board The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900, the association is composed of more than 5,600 schools, colleges, universities, and other educational organizations. Each year, the College Board serves seven million students and their parents, 23,000 high schools, and 3,800 colleges through major programs and services in college admissions, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT®, and the Advanced Placement Program® (AP®). The College Board is committed to the principles of excellence and equity, and that commitment is embodied in all of its programs, services, activities, and concerns. For further information visit www.collegeboard.com. The College Board and the Advanced Placement Program encourage teachers, AP Coordinators, and school administrators to make equitable access a guiding principle for their AP programs. The College Board is committed to the principle that all students deserve an opportunity to participate in rigorous and academically challenging courses and programs. All students who are willing to accept the challenge of a rigorous academic curriculum should be considered for admission to AP courses. The Board encourages the elimination of barriers that restrict access to AP courses for students from ethnic, racial, and socioeconomic groups that have been traditionally underrepresented in the AP Program. Schools should make every effort to ensure that their AP classes reflect the diversity of their student population. © 2009 The College Board. All rights reserved. College Board, Advanced Placement Program, AP, AP Central, SAT, and the acorn logo are registered trademarks of the College Board. PSAT/NMSQT is a registered trademark of the College Board and National Merit Scholarship Corporation. All other products and services may be trademarks of their respective owners. Permission to use copyrighted College Board materials may be requested online at: www.collegeboard.com/inquiry/cbpermit.html. Contents Welcome to the AP Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AP Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AP Exams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AP Course Audit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AP Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AP Exam Grades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Credit and Placement for AP Grades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Credit and Placement Policies for AP Grades . . . . . . . . . . . . . . . . . . . . . . 1 1 1 1 2 2 3 3 AP Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 What We Are About: A Message from the Development Committee . . . . . . . . . 4 The Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Course Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Instructional Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Importance and Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Implementation and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Documenting Laboratory Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Physics B Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Physics C Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Comparison of Topics in Physics B and Physics C . . . . . . . . . . . . . . . . . . . . . . . 12 Content Outline for Physics B and Physics C . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 The Exams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 The Free-Response Sections—Student Presentation . . . . . . . . . . . . . . . . . . . . . . 18 Calculators and Equation Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Physics B Sample Multiple-Choice Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Answers to Physics B Multiple-Choice Questions . . . . . . . . . . . . . . . . . . . . . . 29 Physics B Sample Free-Response Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Physics C: Mechanics Sample Multiple-Choice Questions . . . . . . . . . . . . . . . . . 35 Answers to Physics C: Mechanics Multiple-Choice Questions . . . . . . . . . . . 39 Physics C: Mechanics Sample Free-Response Questions . . . . . . . . . . . . . . . . . . 40 Physics C: Electricity and Magnetism Sample Multiple-Choice Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Answers to Physics C: Electricity and Magnetism Multiple-Choice Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Physics C: Electricity and Magnetism Sample Free-Response Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Teacher Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AP Central (apcentral.collegeboard.com) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AP Publications and Other Resources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Teacher’s Guides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Course Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Released Exams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 54 54 54 54 54 54 i Welcome to the AP® Program For over 50 years, the College Board’s Advanced Placement Program (AP) has partnered with colleges, universities, and high schools to provide students with the opportunity to take college-level course work and exams while still in high school. Offering more than 30 different subjects, each culminating in a rigorous exam, AP provides motivated and academically prepared students with the opportunity to earn college credit or placement and helps them stand out in the college admissions process. Taught by dedicated, passionate AP teachers who bring cutting-edge content knowledge and expert teaching skills to the classroom, AP courses help students develop the study skills, habits of mind, and critical thinking skills that they will need in college. AP is accepted by more than 3,600 colleges and universities worldwide for college credit, advanced placement, or both on the basis of successful AP Exam grades. This includes over 90 percent of four-year institutions in the United States. More information about the AP Program is available at the back of this Course Description and at AP Central®, the College Board’s online home for AP teachers (apcentral.collegeboard.com). Students can find more information at the AP student site (www.collegeboard.com/apstudents). AP Courses More than 30 AP courses in a wide variety of subject areas are now available. A committee of college faculty and master AP teachers designs each AP course to cover the information, skills, and assignments found in the corresponding college course. AP Exams Each AP course has a corresponding exam that participating schools worldwide administer in May. Except for AP Studio Art, which is a portfolio assessment, each AP Exam contains a free-response section (essays, problem solving, oral responses, etc.) as well as multiple-choice questions. Written by a committee of college and university faculty and experienced AP teachers, the AP Exam is the culmination of the AP course and provides students with the opportunity to earn credit and/or placement in college. Exams are scored by college professors and experienced AP teachers using scoring standards developed by the committee. AP Course Audit The intent of the AP Course Audit is to provide secondary and higher education constituents with the assurance that an “AP” designation on a student’s transcript is credible, meaning the AP Program has authorized a course that has met or exceeded the curricular requirements and classroom resources that demonstrate the academic rigor of a comparable college course. To receive authorization from the College Board to label a course “AP,” teachers must participate in the AP Course Audit. Courses authorized to use the “AP” designation are listed in the AP Course Ledger made available to colleges and universities each fall. It is the school’s responsibility to ensure that its AP Course Ledger entry accurately reflects the AP courses offered within each academic year. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 1 The AP Program unequivocally supports the principle that each individual school must develop its own curriculum for courses labeled “AP.” Rather than mandating any one curriculum for AP courses, the AP Course Audit instead provides each AP teacher with a set of expectations that college and secondary school faculty nationwide have established for college-level courses. AP teachers are encouraged to develop or maintain their own curriculum that either includes or exceeds each of these expectations; such courses will be authorized to use the “AP” designation. Credit for the success of AP courses belongs to the individual schools and teachers that create powerful, locally designed AP curricula. Complete information about the AP Course Audit is available at www.collegeboard .com/apcourseaudit. AP Reading AP Exams—with the exception of AP Studio Art, which is a portfolio assessment— consist of dozens of multiple-choice questions scored by machine, and free-response questions scored at the annual AP Reading by thousands of college faculty and expert AP teachers. AP Readers use scoring standards developed by college and university faculty who teach the corresponding college course. The AP Reading offers educators both significant professional development and the opportunity to network with colleagues. For more information about the AP Reading, or to apply to serve as a Reader, visit apcentral.collegeboard.com/readers. AP Exam Grades The Readers’ scores on the free-response questions are combined with the results of the computer-scored multiple-choice questions; the weighted raw scores are summed to give a composite score. The composite score is then converted to a grade on AP’s 5-point scale: AP GRADE 5 4 3 2 1 QUALIFICATION Extremely well qualified Well qualified Qualified Possibly qualified No recommendation AP Exam grades of 5 are equivalent to A grades in the corresponding college course. AP Exam grades of 4 are equivalent to grades of A–, B+, and B in college. AP Exam grades of 3 are equivalent to grades of B–, C+, and C in college. 2 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Credit and Placement for AP Grades Thousands of four-year colleges grant credit, placement, or both for qualifying AP Exam grades because these grades represent a level of achievement equivalent to that of students who have taken the corresponding college course. This college-level equivalency is ensured through several AP Program processes: • College faculty are involved in course and exam development and other AP activities. Currently, college faculty: • Serve as chairs and members of the committees that develop the Course Descriptions and exams in each AP course. • Are responsible for standard setting and are involved in the evaluation of student responses at the AP Reading. The Chief Reader for each AP subject is a college faculty member. • Lead professional development seminars for new and experienced AP teachers. • Serve as the senior reviewers in the annual AP Course Audit, ensuring AP teachers’ syllabi meet the curriculum guidelines of college-level courses. • AP courses and exams are reviewed and updated regularly based on the results of curriculum surveys at up to 200 colleges and universities, collaborations among the College Board and key educational and disciplinary organizations, and the interactions of committee members with professional organizations in their discipline. • Periodic college comparability studies are undertaken in which the performance of college students on AP Exams is compared with that of AP students to confirm that the AP grade scale of 1 to 5 is properly aligned with current college standards. For more information about the role of colleges and universities in the AP Program, visit the Higher Ed Services section of the College Board Web site at professionals .collegeboard.com/higher-ed. Setting Credit and Placement Policies for AP Grades The College Board Web site for education professionals has a section specifically for colleges and universities that provides guidance in setting AP credit and placement policies. Additional resources, including links to AP research studies, released exam questions, and sample student responses at varying levels of achievement for each AP Exam are also available. Visit professionals.collegeboard.com/higher-ed/placement/ap. The “AP Credit Policy Info” online search tool provides links to credit and placement policies at more than 1,000 colleges and universities. This tool helps students find the credit hours and/or advanced placement they may receive for qualifying exam grades within each AP subject at a specified institution. AP Credit Policy Info is available at www.collegeboard.com/ap/creditpolicy. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 3 AP Physics INTRODUCTION What We Are About: A Message from the Development Committee The AP Physics Development Committee recognizes that curriculum, course content, and assessment of scholastic achievement play complementary roles in shaping education at all levels. The committee believes that assessment should support and encourage the following broad instructional goals: 1. Physics knowledge—Basic knowledge of the discipline of physics, including phenomenology, theories and techniques, concepts, and general principles 2. Problem solving—Ability to ask physical questions and to obtain solutions to physical questions by use of qualitative and quantitative reasoning and by experimental investigation 3. Student attributes—Fostering of important student attributes, including appreciation of the physical world and the discipline of physics, curiosity, creativity, and reasoned skepticism 4. Connections—Understanding connections of physics to other disciplines and to societal issues The first three of these goals are appropriate for the AP and introductory-level college physics courses that should, in addition, provide a background for the attainment of the fourth goal. The AP Physics Exams have always emphasized achievement of the first two goals. Over the years, the definitions of basic knowledge of the discipline and problem solving have evolved. The AP Physics courses have reflected changes in college courses, consistent with our primary charge. We have increased our emphasis on physical intuition, experimental investigation, and creativity. We include more openended questions in order to assess students’ ability to explain their understanding of physical concepts. We structure questions that stress the use of mathematics to illuminate the physical situation rather than to show manipulative abilities. The committee is dedicated to developing exams that can be graded fairly and consistently and that are free of ethnic, gender, economic, or other bias. We operate under practical constraints of testing methods, allotted time, and large numbers of students at widely spread geographical locations. In spite of these constraints, the committee strives to design exams that promote excellent and appropriate instruction in physics. THE COURSES The AP Physics Exams are designed to test student achievement in the AP Physics courses described in this book. These courses are intended to be representative of courses commonly offered in colleges and universities, but they do not necessarily correspond precisely to courses at any particular institution. The aim of an AP 4 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. secondary school course in physics should be to develop the students’ abilities to do the following: 1. Read, understand, and interpret physical information—verbal, mathematical, and graphical 2. Describe and explain the sequence of steps in the analysis of a particular physical phenomenon or problem; that is, a. describe the idealized model to be used in the analysis, including simplifying assumptions where necessary; b. state the concepts or definitions that are applicable; c. specify relevant limitations on applications of these principles; d. carry out and describe the steps of the analysis, verbally or mathematically; and e. interpret the results or conclusions, including discussion of particular cases of special interest 3. Use basic mathematical reasoning—arithmetic, algebraic, geometric, trigonometric, or calculus, where appropriate—in a physical situation or problem 4. Perform experiments and interpret the results of observations, including making an assessment of experimental uncertainties In the achievement of these goals, concentration on basic principles of physics and their applications through careful and selective treatment of well-chosen areas is more important than superficial and encyclopedic coverage of many detailed topics. Within the general framework outlined on pages 13–15, teachers may exercise some freedom in the choice of topics. In the AP Physics Exams, an attempt is made through the use of multiple-choice and free-response questions to determine how well these goals have been achieved by the student either in a conventional course or through independent study. The level of the student’s achievement is assigned an AP grade of 1 to 5, and many colleges use this grade alone as the basis for placement and credit decisions. Introductory college physics courses typically fall into one of three categories, designated as A, B, and C in the following discussion. Category A includes courses in which major concepts of physics are covered without as much mathematical rigor as in more formal courses, such as Category B and Category C, which are described below. The emphasis in Category A courses is on developing a qualitative conceptual understanding of general principles and models and on the nature of scientific inquiry. Some courses may also view physics primarily from a cultural or historical perspective. Category A courses are generally intended for students not majoring in a science-related field. The level of mathematical sophistication usually includes some algebra and may extend to simple trigonometry, but rarely beyond. These courses vary widely in content and approach, and at present there is no AP course or exam in this category. A high school version of a Category A course that concentrates on conceptual development and that provides an enriching laboratory experience may be taken by students in the ninth or tenth grade and should provide the first course in physics that prepares them for a more mathematically rigorous AP Physics B or C course. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 5 Category B courses build on the conceptual understanding attained in a first course in physics, such as the Category A course described above. These courses provide a systematic development of the main principles of physics, emphasizing problem solving and helping students develop a deep understanding of physics concepts. It is assumed that students are familiar with algebra and trigonometry, although some theoretical developments may use basic concepts of calculus. In most colleges, this is a one-year terminal course including a laboratory component and is not the usual preparation for more advanced physics and engineering courses. However, Category B courses often provide a foundation in physics for students in the life sciences, premedicine, and some applied sciences, as well as other fields not directly related to science. AP Physics B is intended to be equivalent to such courses. Category C courses also build on the conceptual understanding attained in a first course in physics, such as the Category A course described above. These courses normally form the college sequence that serves as the foundation in physics for students majoring in the physical sciences or engineering. The sequence is parallel to or preceded by mathematics courses that include calculus. Methods of calculus are used in formulating physical principles and in applying them to physical problems. The sequence is more intensive and analytic than in Category B courses. Strong emphasis is placed on solving a variety of challenging problems, some requiring calculus, as well as continuing to develop a deep understanding of physics concepts. A Category C sequence may be a very intensive one-year course in college but often will extend over one and one-half to two years, and a laboratory component is also included. AP Physics C is intended to be equivalent to part of a Category C sequence and covers two major areas: mechanics, and electricity and magnetism, with equal emphasis on both. In certain colleges and universities, other types of unusually high-level introductory courses are taken by a few selected students. Selection of students for these courses is often based on results of AP Exams, other college admission information, or a collegeadministered exam. The AP Exams are not designed to grant credit or exemption for such high-level courses but may facilitate admission to them. Course Selection It is important for those teaching and advising AP students to consider the relation of AP courses to a student’s college plans. In some circumstances it is advantageous to take the AP Physics B course. The student may be interested in studying physics as a basis for more advanced work in the life sciences, medicine, geology, and related areas, or as a component in a nonscience college program that has science requirements. Credit or advanced placement for the Physics B course provides the student with an opportunity either to have an accelerated college program or to meet a basic science requirement; in either case the student’s college program may be enriched. Access to an intensive physics sequence for physics or science majors is another opportunity that may be available. For students planning to specialize in a physical science or in engineering, most colleges require an introductory physics sequence that includes courses equivalent to Physics C. Since a previous or concurrent course in calculus is often required of students taking Physics C, students who expect advanced placement or credit for 6 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. either Physics C exam should attempt an AP course in calculus as well; otherwise, placement in the next-in-sequence physics course may be delayed or even denied. Either of the AP Calculus courses, Calculus AB or Calculus BC, should provide an acceptable basis for students preparing to major in the physical sciences or engineering, but Calculus BC is recommended. Therefore, if such students must choose between AP Physics or AP Calculus while in high school, they should probably choose AP Calculus. There are three separate AP Physics Exams, Physics B, Physics C: Mechanics, and Physics C: Electricity and Magnetism. Each exam contains multiple-choice and freeresponse questions. The Physics B Exam is for students who have taken a Physics B course or who have mastered the material of this course through independent study. The Physics B Exam covers topics in mechanics, electricity and magnetism, fluid mechanics and thermal physics, waves and optics, and atomic and nuclear physics; a single exam grade is reported. Similarly, the two Physics C Exams correspond to the Physics C course sequence. One exam covers mechanics; the other covers electricity and magnetism. Students may take either or both exams, and separate grades are reported. Further descriptions of the AP Physics courses and their corresponding exams in terms of topics, level, mathematical rigor, and typical textbooks are presented in the pages that follow. Information about organizing and conducting AP Physics courses, of interest to both beginning and experienced AP teachers, may be found in the AP Physics Teacher’s Guide. This publication includes practical advice from successful AP teachers. The 2004 AP Physics B and Physics C Released Exams book contains the complete exams, with solutions and grading standards for the free-response sections and sample student responses, as well as statistical data on student performance. For information about ordering these publications and others, see page 54. Additional useful information may be found at AP Central (apcentral.collegeboard.com). Instructional Approaches It is strongly recommended that both Physics B and Physics C be taught as second-year physics courses. A first-year physics course aimed at developing a thorough understanding of important physical principles and that permits students to explore concepts in the laboratory provides a richer experience in the process of science and better prepares them for the more analytical approaches taken in AP courses. However, secondary school programs for the achievement of AP course goals can take other forms as well, and the imaginative teacher can design approaches that best fit the needs of his or her students. In some schools, AP Physics has been taught successfully as a very intensive first-year course; but in this case there may not be enough time to cover the material in sufficient depth to reinforce the students’ conceptual understanding or to provide adequate laboratory experiences. This approach can work for highly motivated, able students but is not generally recommended. Independent study or other first-year physics courses supplemented with extra work for individual motivated students are also possibilities that have been successfully implemented. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 7 If AP Physics is taught as a second-year course, it is recommended that the course meet for at least 250 minutes per week (the equivalent of a 50-minute period every day). However, if it is to be taught as a first-year course, approximately 90 minutes per day (450 minutes per week) is recommended in order to devote sufficient time to study the material to an appropriate depth and allow time for labs. In a school that uses block scheduling, it is strongly recommended that AP Physics B be scheduled to extend over an entire year. A one-year AP course should not be taught in one semester, as this length of time is insufficient for students to properly assimilate and understand the important concepts of physics that are covered in the syllabus. Each of the Physics C courses, but not both, can be taught in one semester. More detailed descriptions about alternate approaches can be found in the Teacher’s Guide. Whichever approach is taken, the nature of the AP course requires teachers to spend time on the extra preparation needed for both class and laboratory. AP teachers should have a teaching load that is adjusted accordingly. Laboratory Importance and Rationale Laborator y experience must be part of the education of AP Physics students and should be included in all AP Physics courses, just as it is in introductory college physics courses. In textbooks and problems, most attention is paid to idealized situations: friction is often assumed to be constant or absent; meters read true values; heat insulators are perfect; gases follow the ideal gas equation. It is in the laboratory that the validity of these assumptions can be questioned, because there the student meets nature as it is rather than in idealized form. Consequently, AP students should be able to: • design experiments; • observe and measure real phenomena; • organize, display, and critically analyze data; • analyze sources of error and determine uncertainties in measurement; • draw inferences from observations and data; and • communicate results, including suggested ways to improve experiments and proposed questions for further study. Laboratory experience is also important in helping students understand the topics being considered. Thus it is valuable to ask students to write informally about what they have done, observed, and concluded, as well as for them to keep well-organized laboratory notebooks. Students need to be proficient in problem solving and in the application of fundamental principles to a wide variety of situations. Problem-solving ability can be fostered by investigations that are somewhat nonspecific. Such investigations are often more interesting and valuable than “cookbook” experiments that merely investigate a well-established relationship and can take important time away from the rest of the course. 8 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Some questions or parts of questions on each AP Physics Exam deal with labrelated skills, such as design of experiments, data analysis, and error analysis, and may distinguish between students who have had laboratory experience and those who have not. In addition, understanding gained in the laboratory may improve students’ test performance overall. Implementation and Recommendations Laboratory programs in both college courses and AP courses differ widely, and there is no clear evidence that any one approach is necessarily best. This diversity of approaches should be encouraging to the high school teacher of an AP course. The success of a given program depends strongly on the interests and enthusiasm of the teacher and on the general ability and motivation of the students involved. Although programs differ, the AP Physics Development Committee has made some recommendations in regard to school resources and scheduling. Since an AP course is a college course, the equipment and time allotted to laboratories should be similar to that in a college course. Therefore, school administrators should realize the implications, in both cost and time, of incorporating serious laboratories into their program. Schools must ensure that students have access to scientific equipment and all materials necessar y to conduct hands-on, college-level physics laborator y investigations as outlined in the teacher’s course syllabus. In addition to equipment commonly included in college labs, students in AP Physics should have adequate and timely access to computers that are connected to the Internet and its many online resources. Students should also have access to computers with appropriate sensing devices and software for use in gathering, graphing, and analyzing laboratory data and writing reports. Although using computers in this way is a useful activity and is encouraged, some initial experience with gathering, graphing, and manipulating data by hand is also important so that students attain a better feel for the physical realities involved in the experiments. And it should be emphasized that simulating an experiment on a computer cannot adequately replace the actual, hands-on experience of doing an experiment. Flexible or modular scheduling is best in order to meet the time requirements identified in the course outline. Some schools are able to assign daily double periods so that laboratory and quantitative problem-solving skills may be fully developed. A weekly extended or double laboratory period is recommended for labs. It is not advisable to attempt to complete high-quality AP laboratory work entirely within standard 45- to 50-minute periods. If AP Physics is taught as a second-year physics course, the AP labs should build on and extend the lab experiences of the first-year course. The important criterion is that students completing an AP Physics course must have had laboratory experiences that are roughly equivalent to those in a comparable introductory college course. Past surveys of introductory college physics courses, both noncalculus and calculus-based, have revealed that on average about 20 percent of the total course credit awarded can be attributed to lab performance; from two to three hours per week are typically devoted to laboratory activities. Secondary schools may have © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 9 difficulty scheduling this much weekly time for lab. However, the college academic year typically contains fewer weeks than the secondary school year, so AP teachers may be able to schedule a few more lab periods during the year than can colleges. Also, college faculty have reported that some lab time occasionally may be used for other purposes. Nevertheless, in order for AP students to have sufficient time for lab, at least one double or extended period per week is recommended for all AP Physics courses. Laboratory activities in colleges and AP courses can involve different levels of student involvement. They can generally be classified as: (1) prescribed or “cookbook,” (2) limited investigations with some direction provided, and (3) open investigations with little or no direction provided. While many college professors believe that labs in the latter two categories have more value to students, they report often being limited in their ability to institute them by large class sizes and other factors. In this respect, AP teachers often have an advantage in being able to offer more open-ended labs to their students. In past surveys, colleges have cited use of the following techniques to assess student lab performance: lab reports, direct observation, written tests designed specifically for lab, lab-related questions on regular lecture tests, lab practical exams, and maintenance of lab notebooks. When the colleges assessed laboratory skills with written test questions, they reported attempting to assess the following skills in order of decreasing frequency: analysis of data, analysis of errors, design of experiments, and evaluation of experiments and suggestions for future investigations. A more detailed laboratory guide is available and can be ordered through AP Central. This guide contains descriptions of a number of experiments that typify the type and level of skills that should be developed by AP students in conducting laboratory investigations. The experiments are not mandatory; they can be modified or similar experiments substituted as long as they assist the student in developing these skills. The AP Physics Teacher’s Guide also provides additional suggestions for the laboratory. The guide mentions specific experiments that other AP teachers have tried and liked and lists publications and other sources of information that may provide additional ideas for low-cost experiments. It will be helpful to experienced AP teachers as well as to those just beginning to teach courses in AP Physics. Documenting Laboratory Experience The laboratory is important for both AP and college students. Students who have had laboratory experience in high school will be in a better position to validate their AP courses as equivalent to the corresponding college courses and to undertake the laboratory work in more advanced courses with greater confidence. Most college placement policies assume that students have had laboratory experience, and students should be prepared to show evidence of their laboratory work in case the college asks for it. Such experience should be documented for the AP course by keeping a lab notebook or a portfolio of lab reports. Students should be encouraged to keep copies of this work and any other work from previous lab experience. Presenting evidence of adequate college-level laboratory experience to the colleges they attend, as an adjunct to their AP grades, can be very useful to students if they desire credit for or exemption from an introductory college course that includes a laboratory. Although colleges can expect that most entering AP students have been exposed to many of the same 10 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. laboratory experiments performed by their own introductory students, individual consultation with students is often used to help determine the nature of their laboratory experience. Physics B Course The Physics B course includes topics in both classical and modern physics. A knowledge of algebra and basic trigonometry is required for the course; the basic ideas of calculus may be introduced in connection with physical concepts, such as acceleration and work. Understanding of the basic principles involved and the ability to apply these principles in the solution of problems should be the major goals of the course. Consequently, the course should utilize guided inquiry and student-centered learning to foster the development of critical thinking skills. Physics B should provide instruction in each of the following five content areas: Newtonian mechanics, fluid mechanics and thermal physics, electricity and magnetism, waves and optics, and atomic and nuclear physics. A content outline and percentage goals for covering each major topic in the exam are on pages 13–15. A more detailed topic outline is contained in the “Learning Objectives for AP Physics,” which can be found on AP Central. Many colleges and universities include additional topics in their survey courses. Some AP teachers may wish to add supplementary material to a Physics B course. Many teachers have found that a good time to do this is late in the year, after the AP Exams have been given. The Physics B course should also include a hands-on laboratory component comparable to introductory college-level physics laboratories, with a minimum of 12 student-conducted laboratory investigations representing a variety of topics covered in the course. Each student should complete a lab notebook or portfolio of lab reports. The school should ensure that each student has a copy of a college-level textbook (supplemented when necessary to meet the curricular requirements) for individual use inside and outside of the classroom. A link to a list of examples of acceptable textbooks can be found on the Physics B course home page on the AP Central Web site. The AP Physics Teacher’s Guide includes some additional suggestions for supplementary books and other materials. Physics C Courses There are two AP Physics C courses—Physics C: Mechanics and Physics C: Electricity and Magnetism, each corresponding to approximately a semester of college work. Mechanics is typically taught first, and some AP teachers may choose to teach this course only. If both courses are taught over the course of a year, approximately equal time should be given to each. Both courses should utilize guided inquiry and studentcentered learning to foster the development of critical thinking skills and should use introductory differential and integral calculus throughout the course. Physics C: Mechanics should provide instruction in each of the following six content areas: kinematics; Newton’s laws of motion; work, energy, and power; systems of particles and linear momentum; circular motion and rotation; and oscillations and gravitation. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 11 Physics C: Electricity and Magnetism should provide instruction in each of the following five content areas: electrostatics; conductors, capacitors, and dielectrics; electric circuits; magnetic fields; and electromagnetism. Content outlines for both courses and percentage goals for covering each major topic in the exams are on pages 13–15. A more detailed topic outline is contained in the “Learning Objectives for AP Physics,” which can be found on AP Central. Most colleges and universities include in similar courses additional topics such as wave motion, kinetic theory and thermodynamics, optics, alternating current circuits, or special relativity. Although wave motion, optics, and kinetic theory and thermodynamics are usually the most commonly included, there is little uniformity among such offerings, and these topics are not included in the Physics C Exams. The Development Committee recommends that supplementary material be added to Physics C when it is possible to do so. Many teachers have found that a good time to do this is late in the year, after the AP Exams have been given. Each Physics C course should also include a hands-on laboratory component comparable to a semester-long introductory college-level physics laboratory. Students should spend a minimum of 20 percent of instructional time engaged in hands-on laboratory work. Each student should complete a lab notebook or portfolio of lab reports. The school should ensure that each student has a calculus-based college-level textbook (supplemented when necessary to meet the curricular requirements) for individual use inside and outside of the classroom. A link to lists of examples of acceptable textbooks can be found on the Physics C course home pages on the AP Central Web site. The AP Physics Teacher’s Guide includes some additional suggestions for supplementary books and other materials. Comparison of Topics in Physics B and Physics C To serve as an aid for devising AP Physics courses and to more clearly identify the specifics of the exams, a detailed topical structure has been developed that relies heavily on information obtained in college surveys. The general areas of physics are subdivided into major categories on pages 13–15, and for each category the percentage goals for each exam are given. These goals should serve only as a guide and should not be construed as reflecting the proportion of course time that should be devoted to each category. Also, for each major category, some important subtopics are listed. The checkmarks indicate the subtopics that may be covered in each exam. Questions for the exam will come from these subtopics, but not all of the subtopics will necessarily be included in every exam, just as they are not necessarily included in every AP or college course. It should be noted that although fewer topics are covered in Physics C than in Physics B, they are covered in greater depth and with greater analytical and mathematical sophistication, including calculus applications. 12 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Content Outline for Physics B and Physics C A more detailed topic outline is contained in the “Learning Objectives for AP Physics,” which can be found on AP Central. Content Area Percentage Goals for Exams Physics B Physics C: Mechanics I. Newtonian Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. Kinematics (including vectors, vector algebra, components of vectors, coordinate systems, displacement, velocity, and acceleration) 1. Motion in one dimension 2. Motion in two dimensions, including projectile motion 35% 100% 7% 18% √ √ √ √ B. Newton’s laws of motion 1. Static equilibrium (first law) 2. Dynamics of a single particle (second law) 3. Systems of two or more objects (third law) 9% √ √ √ 20% √ √ √ C. Work, energy, power 1. Work and work–energy theorem 2. Forces and potential energy 3. Conservation of energy 4. Power 5% √ √ √ √ 14% √ √ √ √ D. Systems of particles, linear momentum 1. Center of mass 2. Impulse and momentum 3. Conservation of linear momentum, collisions 4% 12% √ √ √ √ √ E. Circular motion and rotation 1. Uniform circular motion 2. Torque and rotational statics 3. Rotational kinematics and dynamics 4. Angular momentum and its conservation 4% √ √ 18% √ √ √ √ F. Oscillations and gravitation 1. Simple harmonic motion (dynamics and energy relationships) 2. Mass on a spring 3. Pendulum and other oscillations 4. Newton’s law of gravity 5. Orbits of planets and satellites a. Circular b. General 6% √ 18% √ √ √ √ √ √ √ √ √ √ © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 13 Percentage Goals for Exams Physics B Content Area II. Fluid Mechanics and Thermal Physics. . . . . . . . . . . . . . . . . 15% A. Fluid Mechanics 1. Hydrostatic pressure 2. Buoyancy 3. Fluid flow continuity 4. Bernoulli’s equation 6% √ √ √ √ B. Temperature and heat 1. Mechanical equivalent of heat 2. Heat transfer and thermal expansion 2% √ √ C. Kinetic theory and thermodynamics 1. Ideal gases a. Kinetic model b. Ideal gas law 2. Laws of thermodynamics a. First law (including processes on pV diagrams) b. Second law (including heat engines) 7% √ √ √ √ Physics C: Electricity and Magnetism III. Electricity and Magnetism . . . . . . . . . . . . . . . . . . . . . . . . . . 25% 100% A. Electrostatics 1. Charge and Coulomb’s law 2. Electric field and electric potential (including point charges) 3. Gauss’s law 4. Fields and potentials of other charge distributions 5% √ √ 30% √ √ B. Conductors, capacitors, dielectrics 1. Electrostatics with conductors 2. Capacitors a. Capacitance b. Parallel plate c. Spherical and cylindrical 3. Dielectrics 4% √ 14% √ √ √ √ √ √ √ 7% √ √ 20% √ √ √ √ √ C. Electric circuits 1. Current, resistance, power 2. Steady-state direct current circuits with batteries and resistors only 3. Capacitors in circuits a. Steady state b. Transients in RC circuits 14 √ √ © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Content Area Percentage Goals for Exams Physics B Physics C: Electricity and Magnetism D. Magnetic Fields 1. Forces on moving charges in magnetic fields 2. Forces on current-carrying wires in magnetic fields 3. Fields of long current-carrying wires 4. Biot–Savart law and Ampere’s law 4% √ √ 20% √ √ √ √ √ E. Electromagnetism 1. Electromagnetic induction (including Faraday’s law and Lenz’s law) 2. Inductance (including LR and LC circuits) 3. Maxwell’s equations 5% √ 16% √ IV. Waves and Optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . √ √ 15% A. Wave motion (including sound) 1. Traveling waves 2. Wave propagation 3. Standing waves 4. Superposition 5% √ √ √ √ B. Physical optics 1. Interference and diffraction 2. Dispersion of light and the electromagnetic spectrum 5% √ √ C. Geometric optics 1. Reflection and refraction 2. Mirrors 3. Lenses 5% √ √ √ V. Atomic and Nuclear Physics . . . . . . . . . . . . . . . . . . . . . . . . . A. Atomic physics and quantum effects 1. Photons, the photoelectric effect, Compton scattering, x-rays 2. Atomic energy levels 3. Wave-particle duality B. Nuclear physics 1. Nuclear reactions (including conservation of mass number and charge) 2. Mass–energy equivalence 10% 7% √ √ √ 3% √ √ © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 15 Laboratory and experimental situations: Each exam will include one or more questions or parts of questions posed in a laboratory or experimental setting. These questions are classified according to the content area that provides the setting for the situation, and each content area may include such questions. These questions generally assess some understanding of content as well as experimental skills, as described on the following pages. Miscellaneous: Each exam may include occasional questions that overlap several major topical areas or questions on miscellaneous topics such as identification of vectors and scalars, vector mathematics, graphs of functions, history of physics, or contemporary topics in physics. THE EXAMS The AP Physics B Exam is 3 hours long, divided equally between a 70-question multiple-choice section and a free-response section. The two sections are weighted equally, and a single grade is reported for the B Exam. The free-response section will usually contain 6 or 7 questions. Examples of possible formats are 2 questions of about 17 minutes each and 5 shorter questions of about 11 minutes each, or 4 questions of about 17 minutes each and 2 shorter questions of about 11 minutes each. However, future exams might include a combination of questions of other lengths. Each Physics C Exam is 1 hour and 30 minutes long. A student may take either or both exams, and separate grades are reported for each. The time for each exam is divided equally between a 35-question multiple-choice section and a free-response section; the two sections are weighted equally in the determination of each grade. The usual format for each free-response section has been 3 questions, each taking about 15 minutes. However, future exams might include a larger number of shorter questions. The percentages of each exam devoted to each major category are specified in the preceding pages. Departures from these percentages in the free-response section in any given year are compensated for in the multiple-choice section so that the overall topic distribution for the entire exam is achieved as closely as possible, although it may not be reached exactly. Some questions, particularly in the free-response sections, may involve topics from two or more major categories. For example, a question may utilize a setting involving principles from electricity and magnetism or atomic and nuclear physics, but parts of the question may also involve the application of principles of mechanics to this setting, either alone or in combination with the principles from electricity and magnetism or atomic and nuclear physics. Such a question would not be classified uniquely according to any particular topic but would receive partial classifications by topics in proportion to the principles needed to arrive at the answers. On both exams the multiple-choice section emphasizes the breadth of the students’ knowledge and understanding of the basic principles of physics; the free-response section emphasizes the application of these principles in greater depth in solving more extended problems. In general, questions may ask students to: • determine directions of vectors or paths of particles; • draw or interpret diagrams; 16 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. • interpret or express physical relationships in graphical form; • account for observed phenomena; • interpret experimental data, including their limitations and uncertainties; • construct and use conceptual models and explain their limitations; • explain steps taken to arrive at a result or to predict future physical behavior; • manipulate equations that describe physical relationships; • obtain reasonable estimates; or • solve problems that require the determination of physical quantities in either numerical or symbolic form and that may require the application of single or multiple physical concepts. Laboratory-related questions may ask students to: • design experiments, including identifying equipment needed and describing how it is to be used, drawing diagrams or providing descriptions of experimental setups, or describing procedures to be used, including controls and measurements to be taken; • analyze data, including displaying data in graphical or tabular form, fitting lines and curves to data points in graphs, performing calculations with data, or making extrapolations and interpolations from data; • analyze errors, including identifying sources of errors and how they propagate, estimating magnitude and direction of errors, determining significant digits, or identifying ways to reduce errors; or • communicate results, including drawing inferences and conclusions from experimental data, suggesting ways to improve experiments, or proposing questions for further study. The free-response section of each exam is printed in a separate booklet in which each part of a question is followed by a blank space for the student’s solution. The same questions without the blank answer spaces are printed on green paper as an insert in the exam booklet. This green insert also contains a Table of Information and tables of commonly used equations. The Table of Information, which is also printed near the front of each multiple-choice section, includes numerical values of some physical constants and conversion factors and states some conventions used in the exams. The equation tables are described in greater detail in a later section. The green insert can be removed from the free-response answer booklet and used for reference when answering the free-response questions only. The International System of Units (SI) is used predominantly in both exams. The use of rulers or straightedges is permitted on the free-response sections to facilitate the sketching of graphs or diagrams that might be required in these sections. Since the complete exams are intended to provide the maximum information about differences in students’ achievement in physics, students may find them more difficult © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 17 than many classroom exams. The best way for teachers to familiarize their students with the level of difficulty is to give them actual released exams (both multiple-choice and free-response sections) from past administrations. Information about ordering publications is on page 54. Recent free-response sections can also be found on AP Central, along with scoring guidelines and some sample student responses. The Free-Response Sections—Student Presentation Students are expected to show their work in the spaces provided for the solution for each part of a free-response question. If they need more space, they should clearly indicate where the work is continued or they may lose credit for it. If students make a mistake, they may cross it out or erase it. Crossed-out work and any work shown on the green insert will not be scored, and credit may be lost for incorrect work that is not crossed out. In scoring the free-response sections, credit for the answers depends on the quality of the solutions and the explanations given; partial solutions may receive partial credit, so students are advised to show all their work. Correct answers without supporting work may lose credit. This is especially true when students are asked specifically to justify their answers, in which case the Exam Readers are looking for some verbal or mathematical analysis that shows how the students arrived at their answers. Also, all final numerical answers should include appropriate units. On the AP Physics Exams the words “justify,” “explain,” “calculate,” “what is,” “determine,” “derive,” “sketch,” and “plot” have precise meanings. Students should pay careful attention to these words in order to obtain maximum credit and should avoid including irrelevant or extraneous material in their answers. The ability to justify an answer in words shows understanding of the principles underlying physical phenomena in addition to the ability to perform the mathematical manipulations necessary to generate a correct answer. Students will be directed to justify or explain their answers on many of the questions they encounter on the AP Physics Exams. The words “justify” and “explain” indicate that the student should support the answer with prose, equations, calculations, diagrams, or graphs. The prose or equations may in some cases refer to fundamental ideas or relations in physics, such as Newton’s laws, conservation of energy, Gauss’s law, or Bernoulli’s equation. In other cases, the justification or explanation may take the form of analyzing the behavior of an equation for large or small values of a variable in the equation. The words “calculate,” “what is,” “determine,” and “derive” have distinct meanings on the AP Physics Exams. “Calculate” means that a student is expected to show work leading to a final answer, which may be algebraic but more often is numerical. “What is” and “determine” indicate that work need not necessarily be explicitly shown to obtain full credit. Showing work leading to answers is a good idea, as it may earn a student partial credit in the case of an incorrect answer, but this step may be skipped by the confident or harried student. “Derive” is more specific and indicates that the students need to begin their solutions with one or more fundamental equations, such as those given on the AP Physics Exam equation sheet. The final answer, usually algebraic, is then obtained through the appropriate use of mathematics. 18 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. The words “sketch” and “plot” relate to student-produced graphs. “Sketch” means to draw a graph that illustrates key trends in a particular relationship, such as slope, curvature, intercept(s), or asymptote(s). Numerical scaling or specific data points are not required in a sketch. “Plot” means to draw the data points given in the problem on the grid provided, either using the given scale or indicating the scale and units when none are provided. Additional information about study skills and test-taking strategies can be found at AP Central. Calculators and Equation Tables Policies regarding the use of calculators on the exams take into account the expansion of the capabilities of scientific calculators, which now include not only programming and graphing functions but also the availability of stored equations and other data. For taking the sections of the exams in which calculators are permitted, students should be allowed to use the calculators to which they are accustomed, except as noted below.* On the other hand, they should not have access to information in their calculators that is not available to other students, if that information is needed to answer the questions. Calculators are NOT permitted on the multiple-choice sections of the Physics B and Physics C exams. The purpose of the multiple-choice sections is to assess the breadth of students’ knowledge and understanding of the basic concepts of physics. The multiple-choice questions emphasize conceptual understanding and qualitative applications. However, many physical definitions and principles are quantitative by nature and can therefore be expressed as equations. The knowledge of these basic definitions and principles, expressed as equations, is a part of the content of physics that should be learned by physics students and will continue to be assessed in the multiple-choice sections. However, any numeric calculations using these equations required in the multiple-choice sections will be kept simple. Also, in some questions, the answer choices differ by several orders of magnitude so that the questions can be answered by estimation. Students should be encouraged to develop their skills not only in estimating answers but also in recognizing answers that are physically unreasonable or unlikely. Calculators are allowed on the free-response section of all exams. Any programmable or graphing calculator may be used except as noted below,* and students will not be required to erase their calculator memories before and after the exam. The free-response sections emphasize solving in-depth problems where knowledge of which principles to apply and how to apply them is the most important aspect of the solution to these problems. Regardless of the type of calculator allowed, the exams are designed and scored to minimize the necessity of doing lengthy computations. When free-response problems * Exceptions to calculator use. Calculators that are not permitted are PowerBooks and portable/handheld computers; electronic writing pads or pen-input/stylus-driven devices (e.g., Palm, PDAs, Casio ClassPad 300); pocket organizers; models with QWERTY (i.e., typewriter) keypads (e.g., TI-92 Plus, Voyage 200); models with paper tapes; models that make noise or “talk”; models that require an electrical outlet; cell phone calculators. Students may not share calculators. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 19 involve calculations, most of the points awarded in the grading of the solution are given for setting up the solution correctly rather than for actually carrying out the computation. Tables containing commonly used physics equations are printed in the green insert provided with each exam for students to use when taking the free-response section. The equation tables may NOT be used when taking the multiple-choice section. The Table of Information and the equation tables for the 2010 and 2011 exams are included as an insert in this book so that they can easily be removed and duplicated for use by students. In general, the tables for each year’s exam will be printed and distributed with the Course Description at least a year in advance so that students can become accustomed to using them throughout the year. However, since the equations will be provided with the exams, students are NOT allowed to bring their own copies to the exam room. One of the purposes of providing the commonly used equations is to make the freeresponse sections equitable for those students who do not have access to equations stored in their calculators. The availability of these equations means that in the scoring of the free-response sections little or no credit will be awarded for simply writing down correct equations or for ambiguous answers unsupported by explanations or logical development. The equations in the tables express relationships that are encountered most frequently in AP Physics courses and exams. However, they do not include all equations that might possibly be used. For example, they do not include many equations that can be derived by combining others in the tables. Nor do they include equations that are simply special cases of any that are in the tables. Students are responsible for understanding the physical principles that underlie each equation and for knowing the conditions for which each equation is applicable. The equations are grouped in tables according to major content category. Within each table, the symbols used for the variables in that table are defined. However, in some cases the same symbol is used to represent different quantities in different tables. It should be noted that there is no uniform convention among textbooks for the symbols used in writing equations. The equation tables follow many common conventions, but in some cases consistency was sacrificed for the sake of clarity. In summary, the purpose of minimizing numerical calculations in both sections of the exams and providing equations with the free-response sections is to place greater emphasis on the understanding and application of fundamental physical principles and concepts. For solving problems, a sophisticated programmable or graphing calculator, or the availability of stored equations, is no substitute for a thorough grasp of the physics involved. 20 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics B Physics B Sample Multiple-Choice Questions Most of the following sample questions, illustrative of the Physics B Exam, have appeared in past exams. The answers are on page 29. Additional questions can be found in the 2004 AP Physics B and Physics C Released Exams book. Note: Units associated with numerical quantities are abbreviated, using the abbreviations listed in the table of information included with the exams (see insert in this book.) To simplify calculations, you may use g = 10 m/s2 in all problems. Directions: Each of the questions or incomplete statements below is followed by five suggested answers or completions. Select the one that is best in each case. 1. An object is thrown with a horizontal velocity of 20 m/s from a cliff that is 125 m above level ground. If air resistance is negligible, the time that it takes the object to fall to the ground from the cliff is most nearly (A) 3 s (B) 5 s (C) 6 s (D) 12 s (E) 25 s 2. The motion of a particle along a straight line is represented by the position versus time graph above. At which of the labeled points on the graph is the magnitude of the acceleration of the particle greatest? (A) (B) (C) (D) (E) A B C D E © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 21 Sample Questions for Physics B Questions 3–4 A 2 kg block, starting from rest, slides 20 m down a frictionless inclined plane from X to Y, dropping a vertical distance of 10 m as shown above. 3. The magnitude of the net force on the block while it is sliding is most nearly (A) (B) (C) (D) (E) 4. The speed of the block at point Y is most nearly (A) (B) (C) (D) (E) 22 10.1 N 10.4 N 12.5 N 15.0 N 10.0 N 107 m/s 110 m/s 114 m/s 120 m/s 100 m/s © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics B 5. A block of mass 2 kg slides along a horizontal tabletop. A horizontal applied force of 12 N and a vertical applied force of 15 N act on the block, as shown above. If the coefficient of kinetic friction between the block and the table is 0.2, the frictional force exerted on the block is most nearly (A) (B) (C) (D) (E) 6. 1N 3N 4N 5N 7N A ball of mass M and speed v collides head-on with a ball of mass 2M and speed v , as shown above. If the two balls stick together, their speed after the collision is 2 (A) 0 (B) v 2 (C) ͌2v (D) ͌3v 2 2 (E) 3v 2 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 23 Sample Questions for Physics B 7. A massless rigid rod of length 3d is pivoted at a fixed point W, and two forces each of magnitude F are applied vertically upward as shown above. A third vertical force of magnitude F may be applied, either upward or downward, at one of the labeled points. With the proper choice of direction at each point, the rod can be in equilibrium if the third force of magnitude F is applied at point (A) (B) (C) (D) (E) 8. W only Y only V or X only V or Y only V W, or X , An ideal monatomic gas is compressed while its temperature is held constant. What happens to the internal energy of the gas during this process, and why? (A) It decreases because the gas does work on its surroundings. (B) It decreases because the molecules of an ideal gas collide. (C) It does not change because the internal energy of an ideal gas depends only on its temperature. (D) It increases because work is done on the gas. (E) It increases because the molecules travel a shorter path between collisions. 24 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics B 9. In the pV diagram above, the initial state of a gas is shown at point X. Which of the curves represents a process in which no work is done on or by the gas? (A) (B) (C) (D) (E) XA XB XC XD XE P• •q T• 10. An isolated positive charge q is in the plane of the page, as shown above. The directions of the electric field vectors at points P and T, which are also in the plane of the page, are given by which of the following? (A) (B) (C) (D) (E) Point P Left Right Left Right Left Point T Right Left Toward the top of the page Toward the top of the page Toward the bottom of the page © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 25 Sample Questions for Physics B Questions 11–12 relate to the following circuit in which the battery has zero internal resistance. 11. What is the current in the 4 Ω resistor while the switch S is open? (A) (B) (C) (D) (E) 0A 0.6 A 1.2 A 2.0 A 3.0 A 12. When the switch S is closed and the 10 µF capacitor is fully charged, what is the voltage across the capacitor? (A) (B) (C) (D) (E) 110 V 116 V 112 V 160 V 120 V Flow 1 • • 2 13. A fluid flows steadily from left to right in the pipe shown above. The diameter of the pipe is less at point 2 than at point 1, and the fluid density is constant throughout the pipe. How do the velocity of flow and the pressure at points 1 and 2 compare? (A) (B) (C) (D) (E) 26 Velocity v1 < v2 v1 < v2 v1 = v2 v1 > v2 v1 > v2 Pressure p1 = p2 p1 > p2 p1 < p2 p1 = p2 p1 > p2 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics B 14. Two long parallel wires, separated by a distance d, carry equal currents I toward the top of the page, as shown above. The magnetic field due to the wires at a point halfway between them is (A) (B) (C) (D) (E) zero in magnitude directed into the page directed out of the page directed to the right directed to the left 15. A source S of sound and a listener L each can be at rest or can move directly toward or away from each other with speed v0. In which of the following situations will the observer hear the lowest frequency of sound from the source? (A) S • v= 0 (B) S • v=0 (C) S ৏• vϭv0 (D) S ৏• vϭv0 (E) L • v= 0 L •ৎ vϭv0 L • vϭ0 L •ৎ vϭv0 S L •ৎ ৏ • vϭv0 vϭv0 16. The wavelength of yellow sodium light in vacuum is 5.89 ϫ 10–7 m. The speed of this light in glass with an index of refraction of 1.5 is most nearly (A) (B) (C) (D) (E) 4 ϫ 10–7 m/s 9 ϫ 10–7 m/s 2 ϫ 108 m/s 3 ϫ 108 m/s 4 ϫ 108 m/s © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 27 Sample Questions for Physics B 17. An object O is in front of a convex mirror. The focal point of the mirror is labeled F and the center of curvature is labeled C. The direction of the reflected ray is correctly illustrated in all of the following EXCEPT which diagram? 18. A system initially consists of an electron and an incident photon. The electron and the photon collide, and afterward the system consists of the electron and a scattered photon. The electron gains kinetic energy as a result of this collision. Compared with the incident photon, the scattered photon has (A) (B) (C) (D) (E) 28 the same energy a smaller speed a larger speed a smaller frequency a larger frequency © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics B 19. In an experiment, light of a particular wavelength is incident on a metal surface, and electrons are emitted from the surface as a result. To produce more electrons per unit time but with less kinetic energy per electron, the experimenter should do which of the following? (A) (B) (C) (D) (E) Increase the intensity and decrease the wavelength of the light. Increase the intensity and the wavelength of the light. Decrease the intensity and the wavelength of the light. Decrease the intensity and increase the wavelength of the light. None of the above would produce the desired result. 20. When 10B is bombarded by neutrons, a neutron can be absorbed and an alpha particle (4He) emitted. The kinetic energy of the reaction products is equal to the (A) (B) (C) (D) kinetic energy of the incident neutron total energy of the incident neutron energy equivalent of the mass decrease in the reaction energy equivalent of the mass decrease in the reaction, minus the kinetic energy of the incident neutron (E) energy equivalent of the mass decrease in the reaction, plus the kinetic energy of the incident neutron Answers to Physics B Multiple-Choice Questions 1–B 5–E 9–B 13 – B 17 – D 2–C 6–A 10 – E 14 – A 18 – D 3–E 7–C 11 – B 15 – D 19 – B 4–C 8–C 12 – B 16 – C 20 – E © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 29 Sample Questions for Physics B Physics B Sample Free-Response Questions The following six questions constituted the complete free-response section of the 2006 AP Physics B Exam. All free-response questions released since 1999 can be found at AP Central. Directions: Answer all six questions, which are weighted according to the points indicated. The suggested times are about 17 minutes for answering each of Questions 1–4 and about 11 minutes for answering each of Questions 5–6. The parts within a question may not have equal weight. Show all your work in the pink booklet in the spaces provided after each part, NOT in this green insert. 1. (15 points) An ideal spring of unstretched length 0.20 m is placed horizontally on a frictionless table as shown above. One end of the spring is fixed and the other end is attached to a block of mass M = 8.0 kg. The 8.0 kg block is also attached to a massless string that passes over a small frictionless pulley. A block of mass m = 4.0 kg hangs from the other end of the string. When this spring-and-blocks system is in equilibrium, the length of the spring is 0.25 m and the 4.0 kg block is 0.70 m above the floor. (a) On the figures below, draw free-body diagrams showing and labeling the forces on each block when the system is in equilibrium. M = 8.0 kg m = 4.0 kg (b) Calculate the tension in the string. (c) Calculate the force constant of the spring. The string is now cut at point P. (d) Calculate the time taken by the 4.0 kg block to hit the floor. (e) Calculate the frequency of oscillation of the 8.0 kg block. (f) Calculate the maximum speed attained by the 8.0 kg block. 30 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics B 2. (15 points) A world-class runner can complete a 100 m dash in about 10 s. Past studies have shown that runners in such a race accelerate uniformly for a time tu and then run at constant speed for the remainder of the race. A world-class runner is visiting your physics class. You are to develop a procedure that will allow you to determine the uniform acceleration au and an approximate value of tu for the runner in a 100 m dash. By necessity your experiment will be done on a straight track and include your whole class of eleven students. (a) By checking the line next to each appropriate item in the list below, select the equipment, other than the runner and the track, that your class will need to do the experiment. ____ Stopwatches ____ Tape measures ____ Rulers ____ Masking tape ____ Metersticks ____ Starter’s pistol ____ String ____ Chalk (b) Outline the procedure that you would use to determine au and tu, including a labeled diagram of the experimental setup. Use symbols to identify carefully what measurements you would make and include in your procedure how you would use each piece of the equipment you checked in part (a). (c) Outline the process of data analysis, including how you will identify the portion of the race that has uniform acceleration, and how you would calculate the uniform acceleration. 3. (15 points) Two point charges, q1 and q2, are placed 0.30 m apart on the x-axis, as shown in the figure above. Charge q1 has a value of −3.0 ϫ 10Ϫ9 C . The net electric field at point P is zero. (a) What is the sign of charge q2? ____Positive ____ Negative Justify your answer. (b) Calculate the magnitude of charge q2. (c) Calculate the magnitude of the electric force on q2 and indicate its direction. (d) Determine the x-coordinate of the point on the line between the two charges at which the electric potential is zero. (e) How much work must be done by an external force to bring an electron from infinity to the point at which the electric potential is zero? Explain your reasoning. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 31 Sample Questions for Physics B 4. (15 points) A student performs an experiment to determine the index of refraction n of a rectangular glass slab in air. She is asked to use a laser beam to measure angles of incidence θ i in air and corresponding angles of refraction θ r in glass. The measurements of the angles for five trials are given in the table below. Trial θi θr 1 30º 20º 2 40º 27º 3 50º 32º 4 60º 37º 5 70º 40º (a) Complete the last two columns in the table by calculating the quantities that need to be graphed to provide a linear relationship from which the index of refraction can be determined. Label the top of each column. (b) On the grid below, plot the quantities calculated in (a) and draw an appropriate graph from which the index of refraction can be determined. Label the axes. 32 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics B (c) Using the graph, calculate the index of refraction of the glass slab. The student is also asked to determine the thickness of a film of oil (n = 1.43) on the surface of water (n = 1.33). Light from a variable wavelength source is incident vertically onto the oil film as shown above. The student measures a maximum in the intensity of the reflected light when the incident light has a wavelength of 600 nm. (d) At which of the two interfaces does the light undergo a 180º phase change on reflection? ___The air-oil interface only ___The oil-water interface only ___Both interfaces ___Neither interface (e) Calculate the minimum possible thickness of the oil film. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 33 Sample Questions for Physics B 5. (10 points) A cylinder with a movable frictionless piston contains an ideal gas that is initially in state 1 at 1 ϫ 105 Pa, 373 K, and 0.25 m3. The gas is taken through a reversible thermodynamic cycle as shown in the PV diagram above. (a) Calculate the temperature of the gas when it is in the following states. i. State 2 ii. State 3 (b) Calculate the net work done on the gas during the cycle. (c) Was heat added to or removed from the gas during the cycle? ____ Added ____ Removed ____ Neither added nor removed Justify your answer. 6. (10 points) A photon with a wavelength of 1.5 ϫ 10Ϫ8 m is emitted from an ultraviolet source into a vacuum. (a) Calculate the energy of the photon. (b) Calculate the de Broglie wavelength of an electron with kinetic energy equal to the energy of the photon. (c) Describe an experiment that illustrates the wave properties of this electron. 34 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Mechanics Physics C: Mechanics Sample Multiple-Choice Questions Most of the following sample questions have appeared in past exams. The answers are on page 39. Additional questions can be found in the 2004 AP Physics B and Physics C Released Exams book. Note: Units associated with numerical quantities are abbreviated, using the abbreviations listed in the table of information included with the exams (see insert in this book). To simplify calculations, you may use g = 10 m/s2 in all problems. Directions: Each of the questions or incomplete statements below is followed by five suggested answers or completions. Select the one that is best in each case. Questions 1–2 The speed v of an automobile moving on a straight road is given in meters per second as a function of time t in seconds by the following equation: v = 4 + 2t3 1. What is the acceleration of the automobile at t = 2 s? (A) (B) (C) (D) (E) 2. 12 m/s2 16 m/s2 20 m/s2 24 m/s2 28 m/s2 How far has the automobile traveled in the interval between t = 0 and t = 2 s? (A) (B) (C) (D) (E) 16 m 20 m 24 m 32 m 72 m © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 35 Sample Questions for Physics C: Mechanics 3. If a particle moves in a plane so that its position is described by the functions x = A cos ␻t and y = A sin ␻t, the particle is (A) (B) (C) (D) (E) 4. moving with constant speed along a circle moving with varying speed along a circle moving with constant acceleration along a straight line moving along a parabola oscillating back and forth along a straight line A system in equilibrium consists of an object of weight W that hangs from three ropes, as shown above. The tensions in the ropes are T1, T2, and T3. Which of the following are correct values of T2 and T3? T2 T3 (A) W tan 60° W cos 60° (B) W tan 60° W sin 60° (C) W tan 60° W sin 60° (D) W cos 60° (E) 36 W tan 60° W tan 60° W sin 60° © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Mechanics 5. The constant force F with components Fx = 3 N and Fy = 4 N, shown above, acts on a body while that body moves from the point P (x = 2 m, y = 6 m) to the point Q (x = 14 m, y = 1 m). How much work does the force do on the body during this process? (A) (B) (C) (D) (E) 6. 16 J 30 J 46 J 56 J 65 J The sum of all the external forces on a system of particles is zero. Which of the following must be true of the system? (A) (B) (C) (D) (E) The total mechanical energy is constant. The total potential energy is constant. The total kinetic energy is constant. The total linear momentum is constant. It is in static equilibrium. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 37 Sample Questions for Physics C: Mechanics 7. A toy cannon is fixed to a small cart and both move to the right with speed v along a straight track, as shown above. The cannon points in the direction of motion. When the cannon fires a projectile the cart and cannon are brought to rest. If M is the mass of the cart and cannon combined without the projectile, and m is the mass of the projectile, what is the speed of the projectile relative to the ground immediately after it is fired? (A) Mv m (B) (M + m)v m (C) (M – m)v m (D) mv M (E) 8. A disk X rotates freely with angular velocity ␻ on frictionless bearings, as shown above. A second identical disk Y, initially not rotating, is placed on X so that both disks rotate together without slipping. When the disks are rotating together, which of the following is half what it was before? (A) (B) (C) (D) (E) 38 mv (M – m) Moment of inertia of X Moment of inertia of Y Angular velocity of X Angular velocity of Y Angular momentum of both disks © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Mechanics 9. The ring and the disk shown above have identical masses, radii, and velocities, and are not attached to each other. If the ring and the disk each roll without slipping up an inclined plane, how will the distances that they move up the plane before coming to rest compare? (A) (B) (C) (D) (E) The ring will move farther than will the disk. The disk will move farther than will the ring. The ring and the disk will move equal distances. The relative distances depend on the angle of elevation of the plane. The relative distances depend on the length of the plane. 10. Let g be the acceleration due to gravity at the surface of a planet of radius R. Which of the following is a dimensionally correct formula for the minimum kinetic energy K that a projectile of mass m must have at the planet’s surface if the projectile is to escape from the planet’s gravitational field? (A) K = √gR (B) K = mgR (C) K = mg R (D) K = m g R (E) K = gR Answers to Physics C: Mechanics Multiple-Choice Questions 1–D 3–A 5–A 7–B 9–A 2–A 4–E 6–D 8–C 10 – B © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 39 Sample Questions for Physics C: Mechanics Physics C: Mechanics Sample Free-Response Questions The following three questions constituted the complete free-response section of the 2006 AP Physics C: Mechanics Exam. All free-response questions released since 1999 can be found at AP Central. Directions: Answer all three questions. The suggested time is about 15 minutes for answering each of the questions, which are worth 15 points each. The parts within a question may not have equal weight. Show all your work in the pink booklet in the spaces provided after each part, NOT in this green insert. Mech 1. A small block of mass MB = 0.50 kg is placed on a long slab of mass MS = 3.0 kg as shown above. Initially, the slab is at rest and the block has a speed v0 of 4.0 m/s to the right. The coefficient of kinetic friction between the block and the slab is 0.20, and there is no friction between the slab and the horizontal surface on which it moves. (a) On the dots below that represent the block and the slab, draw and label vectors to represent the forces acting on each as the block slides on the slab. At some moment later, before the block reaches the right end of the slab, both the block and the slab attain identical speeds vf . (b) Calculate vf . (c) Calculate the distance the slab has traveled at the moment it reaches vf . (d) Calculate the work done by friction on the slab from the beginning of its motion until it reaches vf . 40 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Mechanics Mech 2. A nonlinear spring is compressed various distances x, and the force F required to compress it is measured for each distance. The data are shown in the table below. x (m) F (N) 0.05 4 0.10 17 0.15 38 0.20 68 0.25 106 Assume that the magnitude of the force applied by the spring is of the form F(x) = Ax2. (a) Which quantities should be graphed in order to yield a straight line whose slope could be used to calculate a numerical value for A ? (b) Calculate values for any of the quantities identified in (a) that are not given in the data, and record these values in the table above. Label the top of the column, including units. (c) On the axes below, plot the quantities you indicated in (a) . Label the axes with the variables and appropriate numbers to indicate the scale. (d) Using your graph, calculate A. The spring is then placed horizontally on the floor. One end of the spring is fixed to a wall. A cart of mass 0.50 kg moves on the floor with negligible friction and collides head-on with the free end of the spring, compressing it a maximum distance of 0.10 m. (e) Calculate the work done by the cart in compressing the spring 0.10 m from its equilibrium length. (f) Calculate the speed of the cart just before it strikes the spring. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 41 Sample Questions for Physics C: Mechanics Mech 3. A thin hoop of mass M, radius R, and rotational inertia MR 2 is released from rest from the top of the ramp of length L above. The ramp makes an angle θ with respect to a horizontal tabletop to which the ramp is fixed. The table is a height H above the floor. Assume that the hoop rolls without slipping down the ramp and across the table. Express all algebraic answers in terms of given quantities and fundamental constants. (a) Derive an expression for the acceleration of the center of mass of the hoop as it rolls down the ramp. (b) Derive an expression for the speed of the center of mass of the hoop when it reaches the bottom of the ramp. (c) Derive an expression for the horizontal distance from the edge of the table to where the hoop lands on the floor. (d) Suppose that the hoop is now replaced by a disk having the same mass M and radius R. How will the distance from the edge of the table to where the disk lands on the floor compare with the distance determined in part (c) for the hoop? ____ Less than ____ The same as ____ Greater than Briefly justify your response. 42 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Electricity and Magnetism Physics C: Electricity and Magnetism Sample Multiple-Choice Questions Most of the following sample questions have appeared in past exams. The answers are on page 49. Additional questions can be found in the 2004 AP Physics B and Physics C Released Exams book. Note: Units associated with numerical quantities are abbreviated, using the abbreviations listed in the table of information included with the exams (see insert in this book.) Directions: Each of the questions or incomplete statements below is followed by five suggested answers or completions. Select the one that is best in each case. +q • –3a 1. x Two charges are located on the x-axis of a coordinate system as shown above. The charge ϩ2q is located at x = ϩ3a and the charge ϩq is located at x = Ϫ3a. Where on the x-axis should an additional charge ϩ4q be located to produce an electric field equal to zero at the origin O? (A) (B) (C) (D) (E) 2. O +2q • 3a x ϭ Ϫ 6a x ϭ Ϫ 2a xϭϩa x ϭ ϩ 2a x ϭ ϩ 6a A uniform electric field E of magnitude 6,000 V/m exists in a region of space as shown above. What is the electric potential difference, VX – VY , between points X and Y ? (A) –12,000 V (B) 0V (C) 1,800 V (D) 2,400 V (E) 3,000 V © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 43 Sample Questions for Physics C: Electricity and Magnetism 3. 44 Charge is distributed uniformly throughout a long nonconducting cylinder of radius R. Which of the following graphs best represents the magnitude of the resulting electric field E as a function of r, the distance from the axis of the cylinder? © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Electricity and Magnetism 4. A proton p and an electron e are released simultaneously on opposite sides of an evacuated area between large, charged parallel plates, as shown above. Each particle is accelerated toward the oppositely charged plate. The particles are far enough apart so that they do not affect each other. Which particle has the greater kinetic energy upon reaching the oppositely charged plate? (A) (B) (C) (D) The electron The proton Neither particle; both kinetic energies are the same. It cannot be determined without knowing the value of the potential difference between the plates. (E) It cannot be determined without knowing the amount of charge on the plates. 5. Two capacitors initially uncharged are connected in series to a battery, as shown above. What is the charge on the top plate of C1? (A) (B) (C) (D) (E) –81 ␮C –18 ␮C 0 ␮C +18 ␮C +81 ␮C © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 45 Sample Questions for Physics C: Electricity and Magnetism b X 6. • b b •Y Wire of resistivity r and cross-sectional area A is formed into an equilateral triangle of side b, as shown above. The resistance between two vertices of the triangle, X and Y, is (A) 3 A 2 rb (B) 3 A rb (C) 2 rb 3 A (D) 3 rb 2 A (E) 46 3 rb A © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Electricity and Magnetism Questions 7–8 A particle of electric charge +Q and mass m initially moves along a straight line in the plane of the page with constant speed v, as shown above. The particle enters a uniform magnetic field of magnitude B directed out of the page and moves in a semicircular arc of radius R. 7. Which of the following best indicates the magnitude and the direction of the magnetic force F on the charge just after the charge enters the magnetic field? Magnitude kQ2 (A) R2 kQ2 (B) R2 (C) QvB (D) QvB (E) QvB 8. Direction Toward the top of the page Toward the bottom of the page Out of the plane of the page Toward the top of the page Toward the bottom of the page If the magnetic field strength is increased, which of the following will be true about the radius R? I. R increases if the incident speed is held constant. II. For R to remain constant, the incident speed must be increased. III. For R to remain constant, the incident speed must be decreased. (A) (B) (C) (D) (E) I only II only III only I and II only I and III only © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 47 Sample Questions for Physics C: Electricity and Magnetism 9. 48 A bar magnet is lowered at constant speed through a loop of wire as shown in the diagram above. The time at which the midpoint of the bar magnet passes through the loop is t1. Which of the following graphs best represents the time dependence of the induced current in the loop? (A positive current represents a counterclockwise current in the loop as viewed from above.) © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Electricity and Magnetism 10. A loop of wire enclosing an area of 1.5 m 2 is placed perpendicular to a magnetic field. The field is given in teslas as a function of time t in seconds by B(t) = 20t – 5 3 The induced emf in the loop at t = 3 s is most nearly (A) (B) (C) (D) (E) 10 V 15 V 10 V 15 V 20 V Answers to Physics C: Electricity and Magnetism Multiple-Choice Questions 1–A 3–A 5–D 7–E 9–B 2–D 4–C 6–C 8–B 10 – C © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 49 Sample Questions for Physics C: Electricity and Magnetism Physics C: Electricity and Magnetism Sample Free-Response Questions The following three questions constituted the complete free-response section of the 2006 AP Physics C: Electricity and Magnetism Exam. All free-response questions released since 1999 can be found at AP Central. Directions: Answer all three questions. The suggested time is about 15 minutes for answering each of the questions, which are worth 15 points each. The parts within a question may not have equal weight. Show all your work in the pink booklet in the spaces provided after each part, NOT in this green insert. E&M 1. The square of side a above contains a positive point charge +Q fixed at the lower left corner and negative point charges –Q fixed at the other three corners of the square. Point P is located at the center of the square. (a) On the diagram, indicate with an arrow the direction of the net electric field at point P. (b) Derive expressions for each of the following in terms of the given quantities and fundamental constants. i. The magnitude of the electric field at point P ii. The electric potential at point P (c) A positive charge is placed at point P. It is then moved from point P to point R, which is at the midpoint of the bottom side of the square. As the charge is moved, is the work done on it by the electric field positive, negative, or zero? ____ Positive ____ Negative ____ Zero Explain your reasoning. (d) i. Describe one way to replace a single charge in this configuration that would make the electric field at the center of the square equal to zero. Justify your answer. ii. Describe one way to replace a single charge in this configuration such that the electric potential at the center of the square is zero but the electric field is not zero. Justify your answer. 50 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Electricity and Magnetism E&M 2. ␧ The circuit above contains a capacitor of capacitance C, a power supply of emf , two resistors of resistances R1 and R2, and two switches, S1 and S2. Initially, the capacitor is uncharged and both switches are open. Switch S1 then gets closed at time t = 0. (a) Write a differential equation that can be solved to obtain the charge on the capacitor as a function of time t. (b) Solve the differential equation in part (a) to determine the charge on the capacitor as a function of time t. Numerical values for the components are given as follows: ␧ = 12 V C = 0.060 F R1 = R2 = 4700 Ω (c) Determine the time at which the capacitor has a voltage 4.0 V across it. After switch S1 has been closed for a long time, switch S2 gets closed at a new time t = 0. (d) On the axes below, sketch graphs of the current I1 in R1 versus time and of the current I2 in R2 versus time, beginning when switch S2 is closed at new time t = 0. Clearly label which graph is I1 and which is I2. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 51 Sample Questions for Physics C: Electricity and Magnetism E&M 3. A loop of wire of width w and height h contains a switch and a battery and is connected to a spring of force constant k, as shown above. The loop carries a current I in a clockwise direction, and its bottom is in a constant, uniform magnetic field directed into the plane of the page. (a) On the diagram of the loop below, indicate the directions of the magnetic forces, if any, that act on each side of the loop. (b) The switch S is opened, and the loop eventually comes to rest at a new equilibrium position that is a distance x from its former position. Derive an expression for the magnitude B0 of the uniform magnetic field in terms of the given quantities and fundamental constants. 52 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Sample Questions for Physics C: Electricity and Magnetism The spring and loop are replaced with a loop of the same dimensions and resistance R but without the battery and switch. The new loop is pulled upward, out of the magnetic field, at constant speed v0. Express algebraic answers to the following questions in terms of B0, v0, R, and the dimensions of the loop. (c) i. On the diagram of the new loop below, indicate the direction of the induced current in the loop as the loop moves upward. ii. Derive an expression for the magnitude of this current. (d) Derive an expression for the power dissipated in the loop as the loop is pulled at constant speed out of the field. (e) Suppose the magnitude of the magnetic field is increased. Does the external force required to pull the loop at speed v0 increase, decrease, or remain the same? _____ Increases _____ Decreases _____ Remains the same Justify your answer. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. 53 Teacher Support AP Central® (apcentral.collegeboard.com) You can find the following Web resources at AP Central: • AP Course Descriptions, AP Exam questions and scoring guidelines, sample syllabi, and feature articles. • A searchable Institutes and Workshops database, providing information about professional development events. • The Course Home Pages (apcentral.collegeboard.com/coursehomepages), which contain articles, teaching tips, activities, lab ideas, and other course-specific content contributed by colleagues in the AP community. • Moderated electronic discussion groups (EDGs) for each AP course, provided to facilitate the exchange of ideas and practices. AP Publications and Other Resources Free AP resources are available to help students, parents, AP Coordinators, and high school and college faculty learn more about the AP Program and its courses and exams. Visit www.collegeboard.com/apfreepubs. Teacher’s Guides and Course Descriptions may be downloaded free of charge from AP Central; printed copies may be purchased through the College Board Store (store .collegeboard.com). Released Exams and other priced AP resources are available at the College Board Store. Teacher’s Guides For those about to teach an AP course for the first time, or for experienced AP teachers who would like to get some fresh ideas for the classroom, the Teacher’s Guide is an excellent resource. Each Teacher’s Guide contains syllabi developed by high school teachers currently teaching the AP course and college faculty who teach the equivalent course at colleges and universities. Along with detailed course outlines and innovative teaching tips, you’ll also find extensive lists of suggested teaching resources. Course Descriptions Course Descriptions are available for each AP subject. They provide an outline of each AP course’s content, explain the kinds of skills students are expected to demonstrate in the corresponding introductory college-level course, and describe the AP Exam. Sample multiple-choice questions with an answer key and sample free-response questions are included. (The Course Description for AP Computer Science is available in PDF format only.) Released Exams Periodically the AP Program releases a complete copy of each exam. In addition to providing the multiple-choice questions and answers, the publication describes the process of scoring the free-response questions and includes examples of students’ actual responses, the scoring standards, and commentary that explains why the responses received the scores they did. 54 © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. Table of Information and Equation Tables for AP® Physics Exams The accompanying Table of Information and Equation Tables will be provided to students when they take the AP Physics Exams. Therefore, students may NOT bring their own copies of these tables to the exam room, although they may use them throughout the year in their classes in order to become familiar with their content. Table of Information For both the Physics B and Physics C Exams, the Table of Information is printed near the front cover of the multiple-choice section and on the green insert provided with the free-response section. The tables are identical for both exams except for one convention as noted. Equation Tables For both the Physics B and Physics C Exams, the equation tables for each exam are printed only on the green insert provided with the free-response section. The equation tables may be used by students when taking the free-response sections of both exams but NOT when taking the multiple-choice sections. The equations in the tables express the relationships that are encountered most frequently in AP Physics courses and exams. However, the tables do not include all equations that might possibly be used. For example, they do not include many equations that can be derived by combining other equations in the tables. Nor do they include equations that are simply special cases of any that are in the tables. Students are responsible for understanding the physical principles that underlie each equation and for knowing the conditions for which each equation is applicable. The equation tables are grouped in sections according to the major content category in which they appear. Within each section, the symbols used for the variables in that section are defined. However, in some cases the same symbol is used to represent different quantities in different tables. It should be noted that there is no uniform convention among textbooks for the symbols used in writing equations. The equation tables follow many common conventions, but in some cases consistency was sacrificed for the sake of clarity. Some explanations about notation used in the equation tables: 1. The symbols used for physical constants are the same as those in the Table of Information and are defined in the Table of Information rather than in the right-hand columns of the tables. 2. Symbols in bold face represent vector quantities. 3. Subscripts on symbols in the equations are used to represent special cases of the variables defined in the right-hand columns. 4. The symbol D before a variable in an equation specifically indicates a change in the variable (i.e., final value minus initial value). 5. Several different symbols (e.g., d, r, s, h, ) are used for linear dimensions such as length. The particular symbol used in an equation is one that is commonly used for that equation in textbooks. © 2009 The College Board. All rights reserved. College Board, Advanced Placement Program, AP, and the acorn logo are registered trademarks of the College Board. TABLE OF INFORMATION FOR 2010 and 2011 CONSTANTS AND CONVERSION FACTORS 27 10 27 31 1.67 Neutron mass, mn 1.67 Electron mass, me Avogadro’s number, N 0 kg kg Speed of light, Universal gravitational constant, Acceleration due to gravity at Earth’s surface, kg 1.38 10 23 1u Planck’s constant, h hc ⑀0 Vacuum permittivity, Vacuum permeability, Magnetic constant, k 1 atmosphere pressure, UNIT SYMBOLS PREFIXES Factor Prefix Symbol 19 J 8 c 3.00 10 m s G 6.67 10 11 m3 kg s2 9.8 m s2 g mole, hertz, newton, pascal, joule, 10 27 kg 931 MeV c2 6.63 10 34 Js 4.14 1.99 10 25 Jm 1.24 10 12 2 2 1.66 8.85 C Nm 1 4 p⑀0 9.0 4p 10 m0 4 p 1 atm mol Hz N Pa J 10 15 eV s 3 10 eV nm 109 N m 2 C2 m0 Coulomb’s law constant, k m kg s A K C 10 1.60 19 J K 1 unified atomic mass unit, meter, kilogram, second, ampere, kelvin, 10 1.60 1 electron volt, 1 eV 8.31 J (mol K) Boltzmann’s constant, k B e Electron charge magnitude, 1023 mol -1 6.02 R Universal gas constant, 10 9.11 10 Proton mass, m p 1 10 1.0 7 7 (T m) A (T m) A 105 N m 2 watt, coulomb, volt, ohm, henry, W C V W H 1.0 105 Pa farad, tesla, degree Celsius, electron-volt, F T C eV VALUES OF TRIGONOMETRIC FUNCTIONS FOR COMMON ANGLES q 30 0 37 45 53 60 90 10 9 giga G sinq 0 12 35 2 2 4 5 3 2 1 106 mega M cosq 1 3 2 4 5 2 2 35 12 0 103 kilo k tanq 0 3 3 34 1 43 3 10 2 centi c 10 3 milli m 10 6 micro m 10 9 nano n 10 12 pico p The following conventions are used in this exam. I. Unless otherwise stated, the frame of reference of any problem is assumed to be inertial. II. The direction of any electric current is the direction of flow of positive charge (conventional current). III. For any isolated electric charge, the electric potential is defined as zero at an infinite distance from the charge. *IV. For mechanics and thermodynamics equations, W represents the work done on a system. *Not on the Table of Information for Physics C, since Thermodynamics is not a Physics C topic. © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. ADVANCED PLACEMENT PHYSICS B EQUATIONS FOR 2010 and 2011 NEWTONIAN MECHANICS u u0 at x x0 u0 t u2 u0 2 1 2 at 2 2a x F F fric ma Fnet mN ac u2 r t r F sin q p mv J K FDt 1 2 mu 2 DUg W mgh m N P p r T t U u W x m q t = = = = = = = = = = = = = = = = = = = = = = acceleration force frequency height impulse kinetic energy spring constant length mass normal force power momentum radius or distance period time potential energy velocity or speed work done on a system position coefficient of friction angle torque F 1 q1q2 4 p⑀0 r 2 E F q UE F u cos q Fs V C C Uc Us 1 2 kx 2 m k 2p Tp 2p T 1 f FG UG 1 4 p⑀0 g i qi ri Q V ⑀0 A d 1 QV 2 1 CV 2 2 DQ Dt I avg R r A r2 Gm1m2 r e F I P Q q R r t U V = = = = = = = = = = = = = = = = = u = r = q = fm = IV Cp i 1 Cs Rs 1 Rp Ci 1 i Ci Ri i i 1 Ri FB qu B sin q FB Gm1m2 A B C d E IR kx Ts V d Eavg P W Dt 1 q1q2 4 p⑀0 r qV V F Dr cos q Pavg P Dp x0 a F f h J K k ELECTRICITY AND MAGNETISM BI sin q B fm m0 I 2p r BA cos q Dfm Dt eavg e B u © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. area magnetic field capacitance distance electric field emf force current length power charge point charge resistance distance time potential (stored) energy electric potential or potential difference velocity or speed resistivity angle magnetic flux ADVANCED PLACEMENT PHYSICS B EQUATIONS FOR 2010 and 2011 FLUID MECHANICS AND THERMAL PHYSICS WAVES AND OPTICS r mV u fl P P0 n c u r gh Fbuoy rVg A1u1 A2 u2 P D 1 2 ru 2 r gy a const. 0 DT kA DT L H F A P PV nRT Nk BT K avg 3 k T 2 B urms 3 RT M W PDV DU Q 3k B T m e W W QH ec TH A = area e = efficiency F = force h = depth H = rate of heat transfer k = thermal conductivity Kavg = average molecular kinetic energy = length L = thickness m = mass M = molar mass n = number of moles N = number of molecules P = pressure Q = heat transferred to a system T = temperature U = internal energy V = volume u = velocity or speed urms = root-mean-square velocity W = work done on a system y = height a = coefficient of linear expansion m = mass of molecule r = density TC TH ATOMIC AND NUCLEAR PHYSICS E hf K max l DE pc hf f h p ( Dm) c 2 E= f = K= m= p = l= f= energy frequency kinetic energy mass momentum wavelength work function n 1 sin q1 n 2 sin q2 n2 n1 sin qc 1 si 1 s0 M hi h0 R 2 d sin q 1 f si s0 f ml d = separation f = frequency or focal length h = height L = distance M = magnification m = an integer n = index of refraction R = radius of curvature s = distance u = speed x = position l = wavelength q = angle m lL d xm GEOMETRY AND TRIGONOMETRY Rectangle A bh Triangle 1 A bh 2 Circle A pr2 C 2p r Parallelepiped V wh Cylinder V pr2 A= C= V= S = b = h = = w= r = area circumference volume surface area base height length width radius S 2p r 2p r 2 Sphere 4 3 V pr 3 S 4p r 2 Right Triangle a 2 b2 c2 a sin q c b cos q c a tan q b © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. c q a 90 b ADVANCED PLACEMENT PHYSICS C EQUATIONS FOR 2010 and 2011 MECHANICS u u0 at x x0 u0 t u2 u0 2 F 1 2 at 2 2a x x0 ma Fnet dp dt F F dt J Dp mv p F fric mN W F dr K 1 2 mu 2 P dW dt P F v DUg mgh 2 u r ac t r t mr r mr 2 K w q q0 F q dV dr V 1 4 p⑀0 UE Iw C Q V C k ⑀0 A d Cp i 1 Cs I Ci 1 Ci i dQ dt R r A E rJ I Neud A V IR Tp FG at w0 t 1 2 at 2 i 1 q1q2 4 p⑀0 r qV 1 2 kx 2 Ts p qi ri 1 QV 2 T 2p w 1 f UG m k 2p 2p Rs g Gm1m2 r2 Gm1m2 r ˆ r F I J L ⑀0 E P FM n N = = = = = = = = V= u = r = fm = k = P Q q R r t U 1 CV 2 2 area magnetic field capacitance distance electric field emf force current current density inductance length number of loops of wire per unit length number of charge carriers per unit volume power charge point charge resistance distance time potential or stored energy electric potential velocity or speed resistivity magnetic flux dielectric constant B dᐉ m0 I dB I dᐉ Bs m0 nI fm e 1 Ri E dᐉ L UL 1 2 LI 2 IV qv B B B dA e Ri i m0 I d ᐉ r 4p r3 F i 1 Rp = = = = = = = = = = = = A B C d E e Q E dA Uc 1 2 Iw 2 w0 E kx m rw L 1 q1q2 4 p⑀0 r 2 Us Ia r 2 dm u F Fs F rcm acceleration force frequency height rotational inertia impulse kinetic energy spring constant length angular momentum mass normal force power momentum radius or distance position vector period time potential energy velocity or speed work done on a system position coefficient of friction angle torque angular speed angular acceleration w2 r t net I = = = = = = = = = L = m= N = P = p = r = r = T = t = U= u = W= x = m = q = t = w = a = a F f h I J K k ELECTRICITY AND MAGNETISM © 2009 The College Board. All rights reserved. Visit the College Board on the Web: www.collegeboard.com. dI dt d fm dt ADVANCED PLACEMENT PHYSICS C EQUATIONS FOR 2010 and 2011 GEOMETRY AND TRIGONOMETRY Rectangle A bh A= C= V= S = b = h = = w= r = Triangle 1 bh 2 A Circle C 2p r Parallelepiped V wh Cylinder d f du du dx d n x dx nx n d x e dx ex 1 x cos x d cos x dx 2p r n 2 e x dx Sphere 4 3 pr 3 dx x S 4p r 2 cos x dx a2 sin q b2 1 ln x sin x dx sin x cos x c2 a c cos q b c tan q c q xn 1, n ex V Right Triangle sin x 1 x n dx 2p r 1 d 1n x dx pr2 V S df dx area circumference volume surface area base height length width radius d sin x dx pr2 A CALCULUS a 90 b a b © 2009 The College Board. All rights reserved. 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This note was uploaded on 01/10/2011 for the course PHYS 100 taught by Professor Razasuleman during the Spring '10 term at University of Engineering & Technology.

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