Momentum Multiple Choice
1.
A 30.00 kg mass falls from a height of 4.000 m. The momentum of the mass just before it hits the ground
is
A. 144.2 kg m/s.
B. 187.8 kg m/s.
C. 320.0 kg m/s.
D. 442.4 kg m/s.
E. 502.1 kg m/s.
2.
A 3.000 kg ball is pitched with a kinetic energy of 20.00 Joules. Then the momentum of the ball is
A. 7.500 kg m/s.
B. 8.350 kg m/s.
C. 9.450 kg m/s.
D. 10.95 kg m/s.
E. 12.50 kg m/s.
3.
If the momentum of a ball is doubled, then the kinetic energy is
A. 0.5 times larger.
B. 2 times larger.
C. 3 times larger.
D. 4 times larger.
E. 5 times larger.
4.
A 4.00 kg ball is traveling at 5.00 m/s and strikes a wall. The 4.00 kg ball bounces off the wall with a
velocity of 4.0 m/s. The change in momentum of the ball is
A. 8.0 kg m/s.
B. 13 kg m/s.
C. 26 kg m/s.
D. 30 kg m/s.
E. 36 kg m/s.
5.
A machine gun fires 60.0 gram bullets at 6 bullets a second. If the velocity of the bullets is 600 m/s, then
the average force on the machine gun is
A. 67.0 N.
B. 75.0 N.
C. 94.0 N.
D. 109 N.
E. 216 N.
6.
A rifle fires a bullet. Immediately after the bullet is fired, which of the following is NOT true?
A. the rifle and the bullet have the same magnitude of momentum
B. the force on the rifle due to the bullet and the force on the bullet due to the rifle have the same
magnitude
C. the impulse on the rifle due to the bullet and the impulse on the bullet due to the rifle have the same
magnitude
D. the rifle and the bullet do not have the same kinetic energy
E. the rifle and the bullet have the same kinetic energy
7.
A 140 gm baseball with a velocity of 25.0 m/s is hit by a baseball bat and leaves at 30.0 m/s in the
opposite direction. If the ball was in contact with the bat for 12.0 ms, what is the average force on the
ball?
A. 750 N
B. 642 N
C. 550 N
D. 482 N
E. 366 N
8.
Two objects of equal mass hit a wall with the same velocity. They both rebound with the same velocity.
Both objects experience the same momentum change but one experiences twice the force as the other.
Which of the following statements is true?
A. the contact time between the object and the wall of one is twice the contact time of the other
B. the contact time between the object and the wall of one is equal to the contact time of the other
C. the contact time between the object and the wall of one is one-half the contact time of the other
D. the change in the kinetic energy is the same for the two objects
E. the contact time between the object and the wall of one is 1/3 the contact time of the other
9.
A rocket with a mass of 500 grams is launched straight up. It achieves a velocity of 20.0 m/s in 2.00
seconds. The average thrust force of the engines on the rocket is
A. 7.50 N.
B. 9.90 N.
C. 12.0 N.
D. 13.5 N.
E. 20.0 N
10. A 3.0 kg object is moving to the right at 4.0 m/s. It collides in a perfectly inelastic collision with a 6.0 kg
object moving to the left at 2.0 m/s. What is the total kinetic energy after the collision?
A. 62 J
B. 25 J
C. 12 J
D. 0.0 J
11. A 90. kg person is sitting in a boat at rest with a mass of 100 kg. In the boat is a stone with a mass of 5.00
kg. The person throws the stone at 4.00 m/s horizontally in the NORTH direction. The velocity of the
person and the boat after the throwing of the stone is
A. 2.00 m/s NORTH.
B. 1.21 m/s SOUTH.
C. 1.21 m/s NORTH.
D. 0.11 m/s SOUTH.
E. 0.11 m/s NORTH.
12. A 4.00 kg ball is moving at 4.0 m/s to the right and a 6.00 kg ball is moving at 3.00 m/s to the left. The
total momentum of the system is
A. 16 kg m/s to the right.
B. 2.0 kg m/s to the right.
C. 2.0 kg m/s to the left.
D. 18 kg m/s to the left.
E. 34 kg m/s to the left.
13. A 4.00 kg ball is moving at 2.00 m/s to the WEST and a 6.00 kg ball is moving at 2.00 m/s to the
NORTH. The total momentum of the system is
A. 21.6 kg m/s at an angle of 17.7 degrees NORTH of WEST.
B. 14.4 kg m/s at an angle of 45.2 degrees SOUTH of WEST.
C. 21.6 kg m/s at an angle of 45.2 degrees SOUTH of WEST.
D. 14.4 kg m/s at an angle of 56.3 degrees NORTH of WEST.
E. 21.6 kg m/s at an angle of 56.3 degrees NORTH of WEST.
14. An astronaut in a space suit is motionless in outer space. The propulsion unit strapped to her back ejects
some gas with a velocity of 50 m/s. The astronaut recoils with a velocity of 1.0 m/s. If the mass of the
astronaut and space suit after the gas is ejected is 120 kg, the mass of the gas ejected is
A. 1.0 kg.
B. 1.9 kg.
C. 2.4 kg.
D. 3.00 kg.
E. 3.6 kg.
15. A 100 kg mass is blown apart into a 90.0 kg piece and a 10.0 kg piece. After the blast, the two masses are
moving apart with a relative velocity of 100 m/s. The velocity of the 10.0 kg mass after the explosion is
90.0 m/s. The total kinetic energy of the two masses after the explosion is
A. 63,200 J.
B. 45,000 J.
C. 30,400 J.
D. 23,400 J.
E. 4,500 J.
16. An open box-car has a mass of 30,000 kg and is moving on a level railroad track at 4.00 m/s. 1,000 kg of
water falls straight down into the box-car. The velocity of the box-car after the water falls into the box-car
is
A. 7.01 m/s.
B. 6.55 m/s.
C. 5.02 m/s.
D. 3.87 m/s.
E. 2.89 m/s.
17. A 4.0 kg object is moving at 5.0 m/s NORTH. It strikes a 6.0 kg object at rest. The objects have an
elastic collision and move in the NORTH or SOUTH direction. The velocity of the 4.0 kg object after the
collision is
A. 1.0 m/s NORTH.
B. 4.0 m/s NORTH.
C. 1.0 m/s SOUTH.
D. 4.0 m/s SOUTH.
E. 0 m/s.
18. A 4.00 kg object is moving at 3.00 m/s WEST. It strikes a 6.00 kg that is moving WEST at 2.00 m/s. The
objects have a one-dimensional elastic collision in the EAST-WEST direction. The velocity of the 4.00
kg object after the collision is
A. 1.00 m/s WEST.
B. 2.80 m/s EAST.
C. 1.80 m/s WEST.
D. 2.80 m/s WEST.
E. 1.80 m/s EAST.
19. Two objects collide and stick together. Which of the following is false?
A. momentum is conserved
B. kinetic energy is lost
C. kinetic energy is conserved
D. momentum is lost
20. A 1200 kg car is moving at 5.0 m/s EAST. It strikes an 1800 kg car at rest. The cars have an elastic
collision and move in the EAST or WEST direction. The velocity of the 1800 kg car after the collision
is
A. 3.0 m/s WEST.
B. 1.0 m/s EAST.
C. 4.0 m/s EAST.
D. 4.0 m/s WEST.
E. 1.0 m/s WEST.
21. A ball collides with a second ball at rest. After the collision, the first ball comes to rest and the second
ball moves off at the speed of the first ball. In this collision
A. total momentum is not conserved.
B. total kinetic energy is not conserved.
C. total momentum is conserved but total kinetic energy is not conserved.
D. total momentum is not conserved but total kinetic energy is conserved.
E. total momentum and total kinetic energy are conserved and the masses are equal.
22. A 1200 kg car travels at 25.0 m/s and collides head-on in a perfectly inelastic collision with a stationary
2400 kg truck. The kinetic energy lost in the collision is
A. 330,000 J.
B. 250,000 J.
C. 125,000 J.
D. 95,000 J.
E. 75,000 J.
23. A 4.00 kg object is moving at 5.00 m/s NORTH. It strikes a 6.00 kg object that is moving WEST at 2.00
m/s. The objects have a completely inelastic (stick together) collision. The velocity of the 4.00 kg object
after the collision is
A. 2.54 m/s at an angle of 35.0 degrees NORTH of WEST.
B. 1.93 m/s at an angle of 59.0 degrees NORTH of WEST.
C. 1.93 m/s at an angle of 45.0 degrees NORTH of WEST.
D. 2.33 m/s at an angle of 59.0 degrees NORTH of WEST.
E. 2.33 m/s at an angle of 45.0 degrees NORTH of WEST.
24. A 4.00 kg object is moving at 5.00 m/s EAST. It strikes a 6.00 kg that is at rest. The objects have an
elastic collision. The velocity of the 4.00 kg object after the collision is at an angle of 30.0 degrees
SOUTH of EAST. The velocity of the 4.00 kg mass after the collision is
A. 5.78 m/s.
B. 4.56 m/s.
C. 3.55 m/s.
D. 1.67 m/s.
E. 2.66 m/s.
25. In any collision
A. total momentum is not conserved.
B. total kinetic energy is conserved.
C. total momentum is conserved.
D. total momentum is not conserved but total kinetic energy is conserved.
E. total momentum and total kinetic energy are conserved and the masses are equal.
Momentum Multiple Choice Key
1. B
2. D
3. D
4. E
5. E
6. E
7. B
8. A
9. B
10. D
11. D
12. C
13. D
14. C
15. B
16. D
17. C
18. C
19. C
20. C
21. E
22. B
23. D
24. B
25. C
Momentum Multiple Choice Summary
Category
Giambattista - Chapter 07
Section: 7.2 Momentum
Section: 7.3 The Impulse-Momentum Theorem
Section: 7.4 Conservation of Momentum
Section: 7.7 Collisions in One Dimension
Section: 7.8 Collisions in Two Dimensions
# of Questions
25
4
5
7
6
3