Download Name_______________________ Hour___________ Physics

Name_______________________
Hour___________
Physics
Momentum and Energy Test Review
Momentum:
1. What is momentum?
2. Is momentum a scalar or vector quantity?
3. What are the units for momentum?
4. If the total momentum of a system is zero, what must the net external force be? Explain.
5. What is impulse?
6. If an object bounces after it hits another object, is the impulse smaller or larger than if no bouncing had
occurred? Explain.
7. Why are car dashboards padded? Explain in terms of momentum and impulse.
8. What happens to the momentum of a system if an external force acts on it?
9. Object A has a large mass and is moving at 10 m/s. Object B has a small mass and is moving at 10 m/s.
Which object has more momentum?
10. Object A is moving at 10 m/s. It then speeds up to 25 m/s. In which situation does it have more
momentum?
11. If the mass of an object remains constant but the momentum is changing, is the velocity changing? The
acceleration?
12. If the mass of an object remains constant but the momentum is changing is there a force acting on the
object?
13. What is the law of conservation of momentum?
14. If an object is falling toward earth its momentum is changing. But according the law of conservation of
momentum it can’t change. How do you account for this?
15. Two skaters are at rest. What is the total momentum of the two skaters?
16. The skaters face each other and push off each other. One moves to the left, one moves to the right. What
is the total momentum of the skaters now?
17. If an object is at rest what must its momentum be?
18. What is the difference between an elastic and inelastic collision?
19. A 4500 kg car moving west at 15. m/s collides with a 2500. kg car moving north at 10.0 m/s in an inelastic
collision. What is the velocity (speed and direction) of the two objects after the collision?
20. An object with a mass of 65 kg object is moving at 20. m/s . It collides with a wall and bounces back in the
opposite direction with a speed of 17.5 m/s. If the impact lasted 0.025 s, what was the average force that
acted on the ball?
21. A 275 g glider on an air track is moving at 5.9 m/s. It collides with a stationary glider that has a mass of
400. g in an elastic collision. The 275 g glider bounces off in the opposite direction with a speed of 2.6
m/s. What is the speed of the 400. g glider after the collision?
22. A 72 kg basketball player is running at 3.0 m/s while holding a 2.0 kg basketball. The player throws the
basketball at 25 m/s. What is the speed of the player after she throws the basketball?
Work/Energy:
23. What is work? What is the equation for work? What are the units for work?
24. What is power? What is the equation for power? What are the units for power?
25. What type of quantity is work (vector or scalar)?
26. When is work negative? When is it positive?
27. Why type of quantity is energy (vector or scalar)?
28. What is kinetic energy? What is the equation for kinetic energy?
29. What is potential energy? What is the equation for potential energy?
30. What are the units for energy?
31. What does the conservation of energy state? What is the equation we use for the conservation of energy?
32. What is the work energy theorem? What are the two equations we use for the work energy theorem?
33. A force is applied to an object at an angle. What component of the force is doing the work?
34. You apply a force to an object but the object does not move. Have you done work? Explain.
35. If 10 J of work is required to lift an object 10 meters, how many times more work is required to lift the
object 20 meters?
36. How does the work energy theorem allow us to think of kinetic and potential energy?
37. If a certain car is moving at 50 kph and another car is moving at 100 kph, which has the greatest kinetic
energy?
38. A small (lightweight) AND a large (heavy) car are both moving at 50 kph. Which has the greatest kinetic
energy?
39. Would it take more or less power to move a heavy object up a flight of stairs slowly than to move the
same object up a flight up stairs quickly?
40. What happens to an object’s energy if it starts at rest atop a platform and then begins to fall toward
earth?
41. What about the object’s energy is remaining constant?
42. A 130 N force is applied to an object so the object moves 30. m. How much work is done on the object?
43. A 130 N force is applied to an object at an angle of 27o so the object moves 15 m. How much work is done
on the object?
44. A car 4500 kg truck is moving at 15 m/s. What is the truck’s kinetic energy?
45. A 10. kg object is sitting on top of a 3.5 m high platform. How much potential energy does the object
have?
46. A certain drill has 600 kW of power. If it does work for 3 minutes, how much work has it done?
47. Starting at rest a 35 kg child goes down a slide from a height of 3.5 m. What is the child’s speed at the
bottom of the slide?
48. A 2.00 kg mass is dropped over a cliff that is 35.0 m high. What is the object’s kinetic energy when it is 15
meters above the ground?
49. How much work is done to lift a 750 kg bucket of concrete from the ground to a height of 16 m?
50. Assuming no friction and the speed of the cart to be “zero” at position A, what will be the speed
of the cart at position D
A
C
B
45 m
30. m
20. m
D