1. Chapter 6:Circular motion and Gravitation

3. Work out the radial acceleration of the moon around the earth.

4. Ferris wheel

6. Conical Pendulum
Center-seeking Force: Tension
Circular Motion

7. Conical Pendulum

8. No Skidding on a Curve (I)
Center-seeking Force : Static Friction
msmin = ?

9. No Skidding on a Curve (II)
r = 50.0 m C
m = 1000 kg
v = 14.0 m/s

11. No Skidding on Banked Curve
arad +

12. 6-54.When the system rotates about the rod the strings are extended as shown.
The tension in the upper string is 80 N

13. As the bus rounds a flat curve at constant speed, a package suspended from the luggage rack on a string makes an angle with the vertical as shown.

14. Gravitation
Newton’s Law of Gravitation

15. Gravitational attraction
Note: Two particles of different mass exert equally strong gravitational force on each other

16. Gravitational Forces (I)MM
MM ME
FG = G
r 2
‘‘Attractive Force” ME

17. Why is the Aggie not falling off the earth?
Remember there is equally strong attraction between the earth and the Aggie and vice versa

18. Cavendish balance
Cavendish(1798) announced that he has weighted the earth

21. Average Density of the Earth
g = 9.80 m/s2
RE = 6.37 x 106 m
ME = 5.96 x 1024 kg
rE = 5.50 x 103 kg/m3
= 5.50 g/cm3 ~ 2 x rRock

22. Projectile

23. Circular orbit
The larger r then slower the speed and the larger the period

24. Work and Energy

26. Black hole
Steven Hawkins is associated with the department of Physics and Astronomy at TAMU

27. (will be derived later)
How can the sun become a Black Hole? r
This would increase the sun’s mass. There is a second way:
Decrease sun radius