1. Momentum Created by Craig Smiley (Harrison HS, West Lafayette, IN)
Supported by grant PHY
from the National Science Foundation
and by Purdue University

2. Momentum & Impulse

3. Momentum
Two identical race cars are racing around an oval track. Their cruise controls are locked at 95mph. At moment in time illustrated in the picture, do they have the same momentum?
Yes No
Can’t be determined

4. Impulse
A constant unbalance force of 20N acted in the same direction on a cart initially at rest for 2 seconds. An identical experiment is repeated except that the 20N force acted for 3 seconds.
Which cart experienced a greater change in momentum?
The cart in the first experiment
The cart in the second experiment
Both carts experienced the same change
Not enough info

5. Impulse
Suppose a golf ball and a bowling ball are rolling toward you. Both have the same speed, and you exert the same force to stop each. How do the time intervals to stop them compare? A. It takes less time to stop the golf ball. B. Both take the same time. C. It takes more time to stop the golf ball.

6. Impulse
Suppose a golf ball and a bowling ball are rolling toward you. Both have the same momentum, and you exert the same force to stop each. How do the time intervals to stop them compare? A. It takes less time to stop the golf ball. B. Both take the same time. C. It takes more time to stop the golf ball.

7. Impulse-Momentum Theorem
A 0.01kg paintball shot so it is going 80m/s. When it hits you, how much force is exerted?
0.8 N
8 N
80 N
8000 N
Can’t be determined

8. Impulse-Momentum Theorem
A 2,000kg Mack-truck and a 200kg motorcycle start from rest at a stoplight. The truck’s engine exerts 10x the amount of force than the motorcycle’s engine can exert. After 5 seconds, which vehicle changed its momentum more quickly?
Mack-truck
Motorcycle
Both the same
Can’t be determined

9. A batter hits a foul ball
A batter hits a foul ball. The baseball that was approaching him at with a momentum of 40.0 kg(m/s) leaves the bat with a momentum of 30.0 kg(m/s) in a direction perpendicular to the line between the batter and the pitcher. What is the magnitude of the impulse delivered to the baseball? A) 10 Ns B) 35 Ns C) 50 Ns D) 70 Ns E) Can’t be determined

10. Conservation of Momentum
Demos: medicine ball & skateboard, fire-extinguisher & skateboard

11. Is Momentum Conserved?
A hockey puck slides across the ice (ignore friction). The system is defined having only the hockey puck in it. Is the momentum of the system conserved?
Yes No
Can’t be determined

12. Is Momentum Conserved?
Two hockey players collide on the ice (ignore friction). The system is defined as only one of the players. Is the momentum of the system conserved?
Yes No
Can’t be determined

13. Is Momentum Conserved?
Two hockey players collide on the ice (ignore friction). The system is defined as both of the players. Is the momentum of the system conserved?
Yes No
Can’t be determined

14. Is Momentum Conserved?
A hockey player stops quickly by cutting hard against the ice, scraping the ice with his skates (include friction). The system is defined as the player. Is the momentum of the system conserved?
Yes No
Can’t be determined

15. Is Momentum Conserved?
A hockey player takes a slap-shot, hitting the hockey puck with his stick (ignore friction). The system is defined as the hockey puck and stick. Is the momentum of the system conserved?
Yes No
Can’t be determined

16. Is Momentum Conserved?
The referee drops the hockey puck to resume the game. The system is defined as the puck. Is the momentum of the system conserved as the puck is falling? (ignore air-resistance)
Yes No
Can’t be determined

17. Is Momentum Conserved?
The referee drops the hockey puck to resume the game. The system is defined as the puck and the Earth. Is the momentum of the system conserved as the puck is falling? (ignore air-resistance)
Yes No
Can’t be determined

18. Bowling Ball & Bowling Pin
What is the direction of the total momentum of the system before the collision?  
There is no direction
Can’t be determined without numbers

19. Bowling Ball & Bowling Pin
What is the direction of the total momentum of the system after the collision?  
There is no direction
Can’t be determined without numbers

20. Conservation of Momentum
The bowling ball has an initial momentum of 20kg(m/s) to the right before the collision. Afterwards, the bowling ball has a momentum of 15kg(m/s) to the right. What is the momentum (mag & dir) of the bowling pin after the collision?
5kg(m/s) to the right
5kg(m/s) to the left
35kg(m/s) to the right
0.75kg(m/s) to the left

21. Conservation of Momentum
It’s the football game between Harrison vs McCutcheon! The Raider has an initial momentum of 200kg(m/s) to the left, and the Maverick has an initial momentum of 140kg(m/s) to the right. When they collide, they stick together. What is total momentum (mag & dir) of the system consisting of the two players after the collision right after they hit?
60kg(m/s) to the right
60kg(m/s) to the left
340kg(m/s) to the right
340kg(m/s) to the left
Can’t be determined

22. Conservation of Momentum
You are sitting on a cart with a medicine ball, and everything is at rest. You then throw the medicine ball as hard as you can to the right. You roll back to the left slowly. If you include you, the cart, and the ball in the system, was momentum of the system conserved in the horizontal direction?
No, because initially there was no momentum, and afterwards both objects had a momentum.
Yes, because both you/cart and the ball experienced the same amount of force for the same amount of time (internal forces).
Yes, you/cart had the same amount of momentum as the ball did, just in the opposite direction.
Both B & C
None of these

23. Conservation of Momentum
A rocket is traveling upward and has a momentum of 40,000kg(m/s). It separates due to a small explosion into two parts, causing the top part to have a momentum of 50,000kg(m/s) upwards right after separation. What is the momentum (mag & dir) of the bottom part right after separation?
10,000kg(m/s) upward
10,000kg(m/s) downward
90,000kg(m/s) upward
90,000kg(m/s) downward
None of these
Impossible situation

24. Conservation of Momentum
A golf ball has an initial momentum of 1kg m/s to the right and then bounces in the opposite direction off a bowling ball that is initially at rest. This causes the bowling to start rolling with a momentum that is
Less than 1 kg m/s
1 kg m/s
More than 1 kg m/s
Not enough information

25. Bowling Ball & Bowling Pin
Was the total velocity of the system conserved before and after the collision in the previous example?
Yes No
Can’t be determined

26. Conservation of Momentum
The Raider has an initial momentum of 200kg(m/s) to the left, and the Maverick has an initial momentum of 140kg(m/s) to the right. When the Raider tackles the Maverick they stick together. Which one has a greater velocity after they collide?
The Raider
The Maverick
Both have the same
Can’t be determined

27. Conservation of Momentum
The Raider has an initial momentum of 200kg(m/s) to the left, and the Maverick has an initial momentum of 140kg(m/s) to the right. When the Raider tackles the Maverick they stick together. Which one has a greater momentum after they collide?
The Raider
The Maverick
Both have the same
Can’t be determined

28. Conservation of Momentum
The Raider (80kg) has an initial momentum of 200kg(m/s) to the left, and the Maverick (100kg) has an initial momentum of 140kg(m/s) to the right. When the Raider tackles the Maverick they stick together. Which one has a greater initial velocity before they collide?
The Raider
The Maverick
Both have the same
Can’t be determined

29. Conservation of Momentum
The Raider (80kg) has an initial momentum of 200kg(m/s) to the left, and the Maverick (100kg) has an initial momentum of 140kg(m/s) to the right. When the Raider tackles the Maverick they stick together. Which one has a greater momentum after they collide?
The Raider
The Maverick
Both have the same
Can’t be determined

30. Kinetic Energy
A 500kg car going 30m/s crashes into a 1,000kg bus going 2m/s in the opposite direction. The car locks bumpers with the bus and together they move at 3m/s immediately after the collision in the same direction as the car was initially going. The system consist of the car and the bus (ignore affects of friction). What happened to the Kinetic Energy of the system?
KE  gained
KE  stayed the same
KE  lost
Can’t be determined

31. Kinetic Energy
A 500kg car going 30m/s crashes into a 1,000kg bus going 2m/s in the opposite direction. The car locks bumpers with the bus and together they move at 3m/s immediately after the collision in the same direction as the car was initially going. The system consist of the car and the bus (ignore affects of friction). What happened to the momentum of the system?
p  increased
p  conserved
p  decreased
None of these

32. Ball 1 strikes stationary Ball 2 in 1D elastic collision
Ball 1 strikes stationary Ball 2 in 1D elastic collision. The initial momentum of Ball 1, , and the final momentum of Ball 2, , are shown on the graph.
What is the x-component of 𝑝 1 𝑓 ?
A) 0 B)1 C)-1 D)2 E) -2

33. Ball 1 strikes stationary Ball 2 in 2D elastic collision
Ball 1 strikes stationary Ball 2 in 2D elastic collision. The initial momentum of Ball 1, , and the final momentum of Ball 2, , are shown on the graph.
What is the x-component of 𝑝 1 𝑓 ?
A) 0 B)1 C)-1 D)2 E) -2

34. Ball 1 strikes stationary Ball 2 in 2D elastic collision
Ball 1 strikes stationary Ball 2 in 2D elastic collision. The initial momentum of Ball 1, , and the final momentum of Ball 2, , are shown on the graph.
What is the y-component of 𝑝 1 𝑓 ?
A) 0 B)1 C)-1 D)2 E) -2

35. Two balls, labeled 1 and 2, collide
Two balls, labeled 1 and 2, collide. Their initial momenta and the final momentum of ball 1 is shown in the figure.
What is the x-component of the final momentum of ball 2?
A: -2 B: -1 C: 0 D: +1 E: +2

36. Two balls, labeled 1 and 2, collide
Two balls, labeled 1 and 2, collide. Their initial momenta and the final momentum of ball 1 is shown in the figure.
What is the y-component of the final momentum of ball 2?
A: -4 B: -3 C: 0 D: +1 E: +4

37. Two balls, labeled 1 and 2, collide completely inelastically
Two balls, labeled 1 and 2, collide completely inelastically. The initial momentum of ball 1, and the final momentum of both balls is shown in the figure.
What is the y-component of the initial momentum of ball 2?
A: -2 B: 0 C: +1 D: +2 E: +3

38. Two balls, labeled 1 and 2, collide completely inelastically
Two balls, labeled 1 and 2, collide completely inelastically. The initial momentum of ball 1, and the final momentum of both balls is shown in the figure.
What is the x-component of the initial momentum of ball 2?
A: -3 B: -2 C: -1 D: 0 E: +1