Name _________________________________________________ Class ________________ Date _____________
Physics Chapter 9: Momentum and Its Conservation
Read Chapter 9 (p.p.199-211) and then answer the following questions.
1. Define momentum.
2. What two things must an object have to have momentum?
3. Explain how inertia is different than momentum
4. How do you calculate momentum?
5. What is the symbol and unit for momentum?
6. Define impulse.
7. What two things must an object have to have impulse?
8. Explain how impulse is different than momentum
9. How do you calculate impulse?
10. What is the unit for impulse?
11. Are momentum and impulse vector quantities? Explain.
12. Use Newton’s Second Law of Motion (F = ma) and the definition of acceleration (a = d/t)
to derive the relationship between impulse and change in momentum.
13. Write down the Impulse-Momentum Theorem. Explain in words what it means.
14. If a tennis ball is hit by a racket for 0.15 s with a force of 23 N find its (a) beginning
momentum (b) impulse given it by the racket (c) change in momentum (d) final momentum.
15. Explain using the terms momentum and impulse why automobile airbags save lives.
16. A 725 kg compact car is moving at 100 km/h towards the east. Find its momentum.
17. If the driver of the car above applies the brakes for 2 s and the brakes apply an average force
of 5000N. Find the impulse given the car, its change in momentum, its final momentum, and
its final velocity.
18. State Newton’s Third Law of Motion.
19. State the Law of Conservation of Momentum
20. What is a closed system?
21. What is the difference between internal forces and external forces on a system?
22. What is an isolated system?
23. How is an isolated system different from closed system?
24. For the Law of Conservation of Momentum to be true must a system be closed or isolated or
both? Explain.
25. If there is no air in outer space for a rocket to push off of explain how when a rocket fires its
engines in space it can move.