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Momentum review
1. Two carts of masses of 5.0 kilograms and 1.0 kilogram are
pushed apart by a compressed spring. If the 5.0-kilogram cart
moves westward at 2.0 meters per second, the magnitude of the
velocity of the 1.0-kilogram cart will be
A) 2.0 kg-m/s
C) 10. kg-m/s
B) 2.0 m/s
D) 10. m/s
Base your answers to questions 9 through 11on the information
and diagram below.
Block A moves with a velocity of 2 meters per second to
the right, as shown in the diagram, and then collides
elastically with block B, which is at rest. Block A stops
moving, and block B moves to the right after the collision.
2. A 3.0-kilogram steel block is at rest on a friction-less horizontal
surface. A 1.0-kilogram lump of clay is propelled horizontally at
6.0 meters per second toward the block as shown in the diagram
below.
9. What is the total change in momentum of blocks A and B ?
A) 0 kg.-m/s
C) 40 kg.-m/s
Upon collision, the clay and steel block stick together and move
to the right with a speed of
A) 1.5 m/s B) 2.0 m/s C) 3.0 m/s D) 6.0 m/s
3. A 2,400-kilogram car is traveling at a speed of 20. meters per
second. Compared to the magnitude of the force required to stop
the car in 12 seconds, the magnitude of the force required to stop
the car in 6.0 seconds is
A) half as great
C) the same
B) twice as great
D) four times as great
4. If the direction of the velocity of an object is west, the direction
of the momentum of the object is
A) north
B) south
C) east
B) 20 kg.-m/s
D) 200 kg.-m/s
10.If block A is stopped in 0.1 second, the average force acting on
block A is
A) 50 N
B) 100 N
C) 200 N
D) 400 N
11.If the blocks had remained together after collision, their velocity
would have been
A) 1 m/s
B) 2 m/s
C) 0 m/s
D) .5 m/s
12. Base your answer to the following question on the diagram
below which represents two objects at rest on a frictionless
horizontal surface with a spring compressed between them.
When the compressed spring is released, the two objects are
pushed apart.
D) west
5. An object traveling at 4.0 meters per second has a momentum of
16 kilogram-meters per second. What is the mass of the object?
A) 64 kg
B) 20 kg
C) 12 kg
D) 4.0 kg
6. A 0.025-kilogram bullet is fired from a rifle by an unbalanced
force of 200 Newtons. If the force acts on the bullet for 0.1
second, what is the maximum speed attained by the bullet?
A) 5 m/s
B) 20 m/s
C) 400 m/s D) 800 m/s
7. A 0.45-kilogram football traveling at a speed of 22 meters per
second is caught by an 84-kilogram stationary receiver. If the
football comes to rest in the receiver’s arms, the magnitude of
the impulse imparted to the receiver by the ball is
A) 1800 N•s
C) 4.4 N•s
B) 9.9 N•s
D) 3.8 N•s
8. A rocket with a mass of 1,000 kilograms is moving at a speed of
20 meters per second. The magnitude of the momentum is
A) 50 kg-m/s
C) 20,000 kg-m/s
B) 200 kg-m/s
D) 400,000 kg-m/s
What is the velocity of the 2.0-kilogram object after being acted
on by 10. Newton-seconds of impulse?
A) 1.0 m/s B) 2.0 m/s C) 5.0 m/s D) 10. m/s
13. What is the speed of a 1.0 × 103-kilogram car that has a
momentum of 2.0 × 104 kilogram • meters per second east?
A) 5.0 ×10–2 m/s
C) 1.0 × 104 m/s
B) 2.0 × 101 m/s
D) 2.0 × 107 m/s
14. A force of 20. Newtons is exerted on a cart for 10. seconds.
How long must a 50.-newton force act to produce the same
impulse?
A) 10. s
B) 2.0 s
C) 5.0 s
D) 4.0 s
15. An impulse I is applied to an object. The change in the
momentum of the object is
A) I
B) 2I
C) I/2
D) 4I
Momentum review
16. A 1.2-kilogram block and a 1.8-kilogram block are initially at
rest on a frictionless, horizontal surface. When a compressed
spring between the blocks is released, the 1.8-kilogram block
moves to the right at 2.0 meters per second, as shown.
18. The total momentum of a system that consists of a moving
rocket and its exhaust gases will
A) decrease
C) remain the same
B) increase
19. A 40.-kilogram mass is moving across a horizontal surface at
5.0 meters per second. What is the magnitude of the net force
required to bring the mass to a stop in 8.0 seconds?
A) 1.0 N
B) 5.0 N
C) 25 N
D) 40. N
20. The velocity-time graph below represents the motion of a
3-kilogram cart along a straight line. The cart starts at t = 0 and
initially moves north.
What is the speed of the 1.2-kilogram block after the spring is
released?
A) 1.4 m/s B) 2.0 m/s C) 3.0 m/s D) 3.6 m/s
17. Base your answer to the following question on the graph below,
which shows the velocity of a 1,500-kilogram car during a
20-second-time interval.
What is the magnitude of the change in momentum of the cart
between t = 0 and t = 3 seconds?
A) 20 kg × m/s
C) 60 kg × m/s
The impulse applied to the car during time interval AB is
A) 9.0 x 102 N-sec.
C) 6.0 x 103 N-sec.
B) 4.5 x 103 N-sec.
D) 1.5 x 104 N-sec.
B) 30 kg × m/s
D) 80 kg × m/s
Answer Key
Momentum review
1.
D
2.
A
3.
B
4.
D
5.
D
6.
D
7.
B
8.
C
9.
A
10.
C
11.
A
12.
C
13.
B
14.
D
15.
A
16.
C
17.
D
18.
C
19.
C
20.
C