{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Chapter 4 - Chapter4:BasicPhysics...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 4: Basic Physics Sir Isaac Newton (lived 1641--1727) This chapter covers the revolutionary advancements due to probably the most brilliant scientist  who ever lived:  Isaac Newton . His greatest contributions were in all branches of physics. Kepler's  discoveries about elliptical orbits and the planets' non-uniform speeds made it impossible to  maintain the idea of planetary motion as a natural one requiring no explanation. Newton had to  answer some basic questions: What keeps the planets in their elliptical orbits? On our spinning  Earth what prevents objects from flying away when they are thrown in the air? What keeps you  from being hurled off the spinning Earth? Newton's answer was that a fundamental force called  "gravity" operating between all objects made them move the way they do.  Newton developed some basic rules governing the motion of all objects. He used these laws and  Kepler's laws to derive his unifying Law of Gravity. I will first discuss his three laws of motion and  then discuss gravity. Finally, several applications in astronomy will be given. This chapter uses  several math concepts that are reviewed in the mathematics review appendix. If your math skills  are rusty, study the mathematics review appendix and don't hesitate to ask your astronomy  instructor for help. Newton's Laws of Motion
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Motion In order to accurately describe how things move, you need to be careful in how you describe the  motion and the terms you use. Scientists are usually very careful about the words they use to  explain something because they want to accurately represent nature. Language can often be  imprecise and as you know, statements can often be misinterpreted. Because the goal of science  is to find the single true nature of the universe, scientists try to carefully choose their words to  accurately represent what they see. That is why scientific papers can look so "technical" (and  even, introductory astronomy textbooks!)  When you think of motion, you may first think of something moving at a uniform  speed.  The  speed  = (the distance travelled)/(the time it takes). Because the distance is in the top of the  fraction, there is a direct relation between the speed and the distance: the greater the distance  travelled in a given time, the greater is the speed. However, there is an inverse relation between  time and speed (time is in the bottom of the fraction): the  smaller  the time it takes to cover a given  distance, the  greater  the speed must be. Units of speed involve (time unit)/(distance unit), like  m/sec ("meters per second") or mile/hr ("miles per hour"), etc.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern