1. Physics I Class 18
Newton’s Theory of
Gravitation

2. Forces Known to Physics

3. Forces in Physics 1 (so far)

4. Newton’s Theory of Gravitation

5. Newton’s Law of Universal Gravitation

6. Properties of Gravity

7. If Gravity Varies As 1/r2, Where Does g = 9.8 m/s2 Fit In?

8. Gravity is a Conservative Force

9. We Have Two Formulas for Gravitational Potential Energy!

10. Class #18 Take-Away Concepts

11. Class #18 Problems of the Day

12. Answer to Problem 1 for Class #18

13. Class #18 Problems of the Day

14. Answer to Problem 2 for Class #18

15. Activity #18 Gravitation

16. Class #18 Optional Material Part A - Kepler’s Laws of Orbits
Material on Kepler’s Laws
thanks to Professor Dan Sperber

17. Kepler’s Three Laws of Planetary Motion
1. The Law of Orbits: All planets move in elliptical orbits having the Sun at one focus.
2. The Law of Areas: A line joining any planet to the Sun sweeps out equal areas in equal times.
3. The Law of Periods: The square of the period of any planet about the Sun is proportional to the cube of the semi-major axis of its orbit.

18. Kepler’s Three Laws of Planetary Motion

19. The Law of Areas

20. The Law of Periods

21. ENERGY IN CIRCULAR ORBITS

22. Class #18 Optional Material Part B - General Relativity
Material on General Relativity
thanks to Albert Einstein

23. Where Did Newton Go Wrong? (Again!)

24. The Principle of Equivalence

25. The Principle of Equivalence

26. General Theory of Relativity

27. Black Holes

28. If Newton’s Gravity isn’t true, why do we still use it?
Massive Black Holes
In Galaxies
NGC 3377, NGC 3379
And NGC 4486B