State Oregon University
Physics 202 Final Exam Form X
Winter Term, 2010
General directions: Only one sheet of paper (8.5 x 11both sides), with only handwritten notes, may be used during this exam. You may use any kind of calculator, provided that it is not part of a PDA, cell phone, palmtop or laptopand that it is not transmitting any information wirelessly. Physical constants and other possibly useful information are provided here. Answer Question #1 rst.
Physical constants and other possibly useful information: Patm = 1.01 x 10 Pa k = 1.38 x 10 Question #1:
-23 5
g = 9.80 m/s2
J/K
R = 8.31 J/(molK)
= 5.67 x 10 J/(sm2K )
-8
water.4C = 1000 kg/m3 water.4C
4
NA = 6.02 x 10
23
Vcylinder = r2(h) cylinder
S.Asphere = 4r2
What is the Form designation (A, B, C, D, E, F or X) for your examshown at the top of this page? Write this letter in the answer box for Question 1 on the rst answer sheet in the exam booklet.
For questions 2-16: For multiple-choice or true/false items, write the letter of the one best answer in the appropriate box on the answer sheet. For questions best appropriate questions requiring short answers (a word or short phrase only), write those in the spaces provided. Youre graded on your answers onlyno need word short provided. Youre to show work. Assume 3 signicant digits and SI units in all numeric answers unless instructed otherwise.
True/False (10 points each) 2. True or false? A single molecule can have a temperature. F 3. True or false? Eth = Q + W applies to any collection of matter, not to just monatomic ideal gases. T 4. True or false? In a Carnot heat engine, the efciency is 100%. F 5. True or false? If a monatomic ideal gas undergoes isobaric expansion, its thermal energy increases. T 6. True or false? It is possible for a monatomic ideal gas to experience positive heat ow and zero temperature change. T 7. True or false? When a heat pump is operating, the heat owing out of the working uid (gas) is QH. T
Short Answer (10 points each) 8. If a monatomic ideal gas does 100 J of work in an adiabatic process, will the gas get warmer or cooler? Cooler 9. 14.5 moles of a monatomic ideal gas expands isothermally at 50C from 4.00 m3 to 7.00 m3. What is its pressure at the end of this process? 5.56 x 103 Pa 10. When a monatomic ideal gas has an isochoric doubling of temperature, how does its volume No change? change 11. If a certain machine is operating as a refrigerator with a coefcient of performance of 1.00, what is its coefcient of performance as a heat pump during that operation? 2.00 12. Complete this equation for a monatomic ideal gas: (N)[(1/2)mparticlevrms2] = Eth (or thermal energy; or (3/2)NkT; or (3/2)nRT) therm 13. A Carnot heat engine rejects 3/4 of the heat it receives. If it receives the heat from a source at 100C, what is the Celsius temperature at which it rejects heat? 6.75C (values accepted from 6.71C to 6.75C)
Multiple Choice (10 points each) 14. A certain monatomic ideal gas undergoes a process undergoes that can be represented on a P-V graph by a straight line between the following two points: Pi = 200,000 Pa; Vi = 3.00 m3; Pf = 350,000 Pa; Vf = 2.00 m3. The heat ow to the gas during this process is... (A) (B) (C) (D) positive. negative. zero. There is not enough information to answer.
15. How does the entropy of hot coffee change as it cools? (A) (B) (C) (D) It increases. It decreases. It It does not change. There is not enough information to answer.
16. Heat ows only from a warmer body to a colder bodynever the other way. This is one way to state.. (A) (B) (C) (D) (E) the Zeroeth Law of Thermodynamics. the First Law of Thermodynamics. the Second Law of Thermodynamics. the Third Law of Thermodynamics. Murphys Law.
17. (50 points total) This problem appeared this year as HW6-7, problem #2. Its solution is now posted, along with the rest of that HW set.
18. (50 points total) This problem appeared this year as HW6-7, problem #12. Its solution is now posted, along with the rest of that HW set.
Note: Ten (10) points of Extra Credit are availablefor doing all of the following legibly and correctly (no partial credit): 1. On the cover sheet: PRINT your full last name LEGIBLY in the space provided. RINT 2. On the cover sheet: Write your full OSU ID number (NOT your Social Security # or any other number) in the space provided. 3. On the cover sheet: Sign your name in the space provided. 4. On the cover sheet: In the bottom right corner of that cover page, write +10 and circle it. bottom cir 5. When turning in your exam, you must show your current OSU I.D. to the proctor. 6. Then you must have a safe and restful spring break. Thank you for all your hard work in this course. restful Thank
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