**
Gravity/Friction/Momentum **
**Review 1**

1. What __two__
factors determine the amount of friction between two objects?

2. Explain why a female pro golfer can hit a golf ball further than the average NFL linebacker. (show equation)

3. If an object is moving with a velocity of 5 m/s south, what is the direction of the object's momentum?

___________________

a) How does the direction of an objects motion compare to the direction of the friction force? _______

4. What happens to each of the following quantities when we move away from the earth?

** M**ass
_____ Weight ____ Force from the earth _______

5. What are the units for each of the following quantities?

** M**ass
_____ Weight _____ Force from the earth ______

6. Write the gravity equation ___________________________________

7. How would the force of gravity between the earth and moon change if you:

a) tripled the mass of the earth (moon unchanged) _______ b) doubled the mass of the moon only _______

c) tripled the mass of the
earth **and** doubled the mass of the moon _______

d) Quadrupled the distance between the moon and earth _________

e) Doubled the mass of the earth and moon and doubled their separation distance. ______

8. Compare the earths force on you with your force on the earth.

9. At constant speed the applied force on an object = _______________

10. Scalar (S) or Vector (V) ?? - momentum ____impulse ____ Force of Gravity____ mass_____ Friction_____

11. Be able to create the big momentum equation (from your notes) J = Ft = ________ = _____

12. A constant braking force of 5 N is applied for 5 seconds is used to stop a 10 kg cart traveling at 2.5 m/s. The magnitude of the impulse applied to stop the cart is …

13. All things being equal, which 2 materials on the reference table would produce the

greatest amount of friction? ____________________ least? __________________

Try http://www.123physics.com for more practice questions