Deck 7: Linear Momentum

Question 1

Choose the one alternative that best completes the statement or answers the question.
In a collision between two unequal masses, which mass receives a greater magnitude impulse?

A) the smaller mass
B) the larger mass
C) They receive equal impulses.

Answer 1

They receive equal impulses.

Question 2

Choose the one alternative that best completes the statement or answers the question.
Two friends are standing on opposite ends of a canoe that is initially at rest with respect to a frictionless lake. The person in the front throws a very massive ball toward the back, and the
Person in the back catches it. After the ball is caught, the canoe is

A) moving forward.
B) stationary.
C) moving backward.

Answer 2

stationary.

Question 3

Choose the one alternative that best completes the statement or answers the question.
A very light ping-pong ball moving east at a speed of 4 m/s collides with a very heavy stationary bowling ball. The Ping-Pong ball bounces back to the west, and the bowling ball moves very
Slowly to the east. Which object experiences the greater magnitude impulse during the collision?

A) the Ping-Pong ball
B) the bowling ball
C) Neither; both experienced the same magnitude impulse.
D) It is impossible to tell since the actual mass values are not given.
E) It is impossible to tell since the velocities after the collision are unknown.

Answer 3

Neither; both experienced the same magnitude impulse.

Question 4

Choose the one alternative that best completes the statement or answers the question.
A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the magnitude of the momentum change during the collision is correct? (There could
Be more than one correct choice.)

A) The truck experiences the greater magnitude momentum change.
B) The small car and the truck experience the same magnitude momentum change.
C) The magnitude of the momentum change experienced by each one is directly proportional to its mass.
D) The magnitude of the momentum change experienced by each one is inversely proportional to its mass.
E) The small car experiences the greater magnitude momentum change.

Question 5

Choose the one alternative that best completes the statement or answers the question.
A tiger is running in a straight line. If we double both the mass and speed of the tiger, the magnitude of its momentum will increase by what factor?

A) 2
B) 4
C) 16
D) $\sqrt { 2 }$
E) 8

Question 6

Choose the one alternative that best completes the statement or answers the question.
A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the momentum during the collision are correct? (There could be more than one correct
Choice.)

A) The momentum of the truck is conserved.
B) The momentum of the car and the momentum of the truck are each conserved.
C) The momentum of the car is conserved.
D) The car and the truck must undergo the same change in speed.
E) The momentum of the car-truck system is conserved, but the momentum of each one separately is not conserved.

Question 7

Choose the one alternative that best completes the statement or answers the question.
During World War I, Germany used a "Big Bertha" cannon to hurl shells into Paris 30 miles away. This gun also had a very long barrel. What was the reason for using a long barrel in these guns?

A) to reduce the force exerted on the bullet due to the expanding gases from the gunpowder
B) to reduce frictional losses
C) to increase the force exerted on the bullet due to the expanding gases from the gunpowder
D) to allow the force of the expanding gases from the gunpowder to act for a longer time
E) to exert a larger force on the shells

Question 8

Choose the one alternative that best completes the statement or answers the question.
A rocket explodes into two fragments, one 25 times heavier than the other. The magnitude of the momentum change of the lighter fragment is

A) The same as the momentum change of the heavier fragment.
B) 25 times as great as the momentum change of the heavier fragment.
C) 1/4 as great as the momentum change of the heavier fragment.
D) 5 times as great as the momentum change of the heavier fragment.
E) 1/25 as great as the momentum change of the heavier fragment.

Question 9

Choose the one alternative that best completes the statement or answers the question.
A 5-kg ball collides inelastically head-on with a 10-kg ball, which is initially stationary. Which of the following statements is true? (There could be more than one correct choice.)

A) The magnitude of the change of the momentum of the 5-kg ball is equal to the magnitude of the change of momentum of the 10-kg ball.
B) The magnitude of the change of velocity the 5-kg ball experiences is greater than that of the 10-kg ball.
C) Both balls lose all their momentum since the collision is inelastic.
D) The magnitude of the change of velocity the 5-kg ball experiences is equal to that of the 10-kg ball.
E) The magnitude of the change of velocity the 5-kg ball experiences is less than that of the 10-kg ball.

Question 10

Choose the one alternative that best completes the statement or answers the question.
A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The clay sticks to the
Wall. Which one of these objects experiences the greater momentum change?

A) the ball
B) the clay
C) Both of them experience the same non-zero momentum change.
D) Both of them experience zero momentum change.

Question 11

Choose the one alternative that best completes the statement or answers the question.
Which of the following quantities are units of impulse? (There could be more than one correct choice.)

A) $k q \cdot m^{2} / s^{2}$

B) $N \cdot s$
C) $\mathrm { kg } \cdot \mathrm { s } / \mathrm { m }$
D) $\mathrm { kq } \cdot \mathrm { m } / \mathrm { s }$
E) $\mathrm { N } \cdot \mathrm { m }$

Question 12

Choose the one alternative that best completes the statement or answers the question.
You are standing on a skateboard, initially at rest. A friend throws a very heavy ball towards you. You have two choices about what to do with the ball: either catch the ball or deflect it back toward
Your friend with the same speed as it was originally thrown. Which choice should you make in
Order to maximize your speed on the skateboard?

A) Deflect the ball back.
B) Catch the ball.
C) Your final speed on the skateboard will be the same regardless whether you catch the ball or deflect the ball.

Question 13

Choose the one alternative that best completes the statement or answers the question.
Identical forces act for the same length of time on two different objects. The magnitude of the change in momentum of the lighter object is

A) exactly equal to the magnitude of the change in momentum of the larger mass.
B) smaller than the magnitude of the change in momentum of the larger mass, but not zero.
C) zero.
D) larger than the magnitude of the change in momentum of the larger mass.
E) There is not enough information to answer the question.

Question 14

Choose the one alternative that best completes the statement or answers the question.
Which of the following quantities are units of momentum? (There could be more than one correct choice.)

A) $\mathrm { N } \cdot \mathrm { S }$
B) $\mathrm { N } \cdot \mathrm { m }$
C) $\mathrm { kg } \cdot \mathrm { m } ^ { 2 } / \mathrm { s } ^ { 2 }$
D) $\mathrm { kg } \cdot \mathrm { s } / \mathrm { m }$
E) $\mathrm { kg } \cdot \mathrm { m } / \mathrm { s }$

Question 15

Choose the one alternative that best completes the statement or answers the question.
Consider two less-than-desirable options. In the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. In the second option you are driving 30 mph and crash
Head-on into a stationary brick wall. In neither case does your car bounce back from the thing it
Hits, and the collision time is the same in both cases. Which of these two situations would result in
The greater impact force on your car?

A) hitting the brick wall
B) The force would be the same in both cases.
C) hitting the other car
D) None of the above choices are correct.

Question 16

Choose the one alternative that best completes the statement or answers the question.
Three cars, car X , car Y , and car Z , begin accelerating from rest at the same time. Car X is more massive than car Y , which is more massive than car Z . The net accelerating force exerted on each car is identical. After 10 seconds, which car has the most amount of momentum?

A) They all have the same amount of momentum.
B) Car X
C) Car Y
D) Car Z

Question 17

Choose the one alternative that best completes the statement or answers the question.
A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the magnitude of the average force during the collision is correct?

A) The small car and the truck experience the same average force.
B) The small car experiences the greater average force.
C) The force experienced by each one is directly proportional to its mass.
D) The truck experiences the greater average force.
E) The force experienced by each one is inversely proportional to its mass.

Question 18

Choose the one alternative that best completes the statement or answers the question.
A very elastic rubber ball is dropped from a certain height and hits the floor with a downward speed v. Since it is so elastic, the ball bounces back with the same speed v going upward. Which of
The following statements about the bounce are correct? (There could be more than one correct
Choice.)

A) The ball had the same momentum just before and just after the bounce.
B) The ball's momentum was conserved during the bounce.
C) The magnitude of the ball's momentum was the same just before and just after the bounce.
D) None of the above statements are correct.

Question 19

Choose the one alternative that best completes the statement or answers the question.
In an inelastic collision involving an isolated system, the final total momentum is

A) more than the initial momentum.
B) less than the initial momentum.
C) exactly the same as the initial momentum.

Question 20

Choose the one alternative that best completes the statement or answers the question.
The momentum of an isolated system is conserved

A) only in elastic collisions.
B) in both elastic and inelastic collisions.
C) only in inelastic collisions.

Question 21

Choose the one alternative that best completes the statement or answers the question.
Three objects are moving along a straight line as shown in the figure. Taking the positive direction to be to the right, what is the total momentum of this system?

A) $- 14.0 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
B) $+ 14.0 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $+ 106 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $0.00 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
E) $- 106 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 22

Choose the one alternative that best completes the statement or answers the question.
A 0.14-kg baseball is dropped from rest from a height of 2.0 m above the ground. What is the magnitude of its momentum just before it hits the ground if we neglect air resistance?

A) $0.28 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
B) $0.44 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $0.62 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $0.88 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
E) $1.4 \mathrm { kq } \cdot \mathrm { m } / \mathrm { s }$

Question 23

Choose the one alternative that best completes the statement or answers the question.
In a game of pool, the white cue ball hits the #5 ball and stops, while the #5 ball moves away with the same velocity as the cue ball had originally. Both balls have the same mass. This type of collision is

A) completely inelastic.
B) elastic.
C) somewhat inelastic.

Question 24

Choose the one alternative that best completes the statement or answers the question.
A 0.330-kg volleyball is thrown vertically downward with a speed of 0.150 m/s in a place where g = $9.81 \mathrm {~m} / \mathrm { s } ^ { 2 }$ It takes it 0.0655 s to reach the ground. What is the magnitude of its momentum just before it hits the ground?

A) $0.0418 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
B) $0.0216 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $0.212 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $0.163 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
E) $0.262 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 25

Choose the one alternative that best completes the statement or answers the question.
A railroad car collides with and sticks to an identical railroad car that is initially at rest. After the collision, the kinetic energy of the system

A) is one quarter as much as before.
B) is the same as before.
C) is one third as much as before.
D) is one fourth as much as before.
E) is half as much as before.

Question 26

Choose the one alternative that best completes the statement or answers the question.
In the figure showing an isolated system, determine the character of the collision. The masses of the blocks, and the velocities before and after, are shown. The collision is

A) partially inelastic.
B) completely inelastic.
C) perfectly elastic.
D) characterized by an increase in kinetic energy.
E) not possible because momentum is not conserved.

Question 27

Choose the one alternative that best completes the statement or answers the question.
In the figure, determine the character of the collision. The masses of the blocks, and the velocities before and after, are shown. The collision is

A) completely inelastic.
B) perfectly elastic.
C) partially inelastic.
D) characterized by an increase in kinetic energy.
E) not possible because momentum is not conserved.

Question 28

Choose the one alternative that best completes the statement or answers the question.
A firecracker explodes in midair and breaks up into many fragments. Which of the following statements are true regarding conditions immediately before and immediately after the explosion:
I. The total momentum of the fragments is equal to the original momentum of the firecracker.
II. The total kinetic energy of the fragments is equal to the original kinetic energy of the firecracker.

A) Statement I only
B) Statement II only
C) Both Statement I and Statement II
D) Neither statement is true.

Question 29

Choose the one alternative that best completes the statement or answers the question.
A 2.0-kg ball moving eastward at 3.0 m/s suddenly collides with and sticks to a 4.0-kg ball moving northward at 2.0 m/s. What is the magnitude of the momentum of this system just after the collision?

A) $6.0 \mathrm{~kg}=\mathrm{m} / \mathrm{s}$
B) $8.0 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $10 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $14 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
E) $2.0 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 30

Write the word or phrase that best completes each statement or answers the question.
What is the magnitude of the momentum of a 0.140 kg baseball traveling at 45.0 m/s?

Question 31

Choose the one alternative that best completes the statement or answers the question.
If you want to double the momentum of a gas molecule, by what factor must you increase its kinetic energy?

A) 2
B) 4
C) $2 \sqrt { 2 }$
D) $\sqrt { 2 }$
E) 16

Question 32

Choose the one alternative that best completes the statement or answers the question.
Two objects of different mass have equal, non-zero kinetic energies. Which object has the greater magnitude momentum?

A) the lighter object
B) the heavier object
C) They both have the same magnitude momentum.

Question 33

Choose the one alternative that best completes the statement or answers the question.
If a quantity you calculated had units of kg · m/s, what type of quantity could it be? (There could be more than one correct choice.)

A) impulse
B) work
C) kinetic energy
D) momentum
E) force

Question 34

Choose the one alternative that best completes the statement or answers the question.
On a horizontal frictionless air table, a puck runs into an ideal horizontal spring that is fastened to the table. The puck compresses the spring by 15 cm before coming to rest. During the compression
Process, which quantities are conserved?

A) only the momentum of the puck
B) the momentum and the mechanical energy of the puck
C) only the kinetic energy of the puck
D) the momentum and the kinetic energy of the puck
E) only the mechanical energy (kinetic plus potential) of the puck

Question 35

Choose the one alternative that best completes the statement or answers the question.
If you want to double the kinetic energy of a gas molecule, by what factor must you increase its momentum?

A) 16
B) 4
C) 2
D) $\sqrt { 2 }$
E) $2 \sqrt { 2 }$

Question 36

Choose the one alternative that best completes the statement or answers the question.
Two objects of different masses have momentum of equal, non-zero magnitude. Which object has more kinetic energy?

A) the lighter object
B) the heavier object
C) They both have the same kinetic energy.

Question 37

Choose the one alternative that best completes the statement or answers the question.
There must be equal amounts of mass on both sides of the center of mass (or center of gravity) of a
system.

Question 38

Choose the one alternative that best completes the statement or answers the question.
A rubber ball bounces off of a wall with an initial speed v and reverses its direction so its speed is v right after the bounce. As a result of this bounce, which of the following quantities of the ball are
Conserved? (There could be more than one correct choice.)

A) both the momentum and the kinetic energy of the ball
B) the momentum of the ball
C) the kinetic energy of the ball
D) None of the above quantities are conserved.

Question 39

Choose the one alternative that best completes the statement or answers the question.
In the figure, determine the character of the collision. The masses of the blocks, and the velocities before and after, are shown. The collision is

A) completely inelastic.
B) partially inelastic.
C) perfectly elastic.
D) characterized by an increase in kinetic energy.
E) not possible because momentum is not conserved.

Question 40

Choose the one alternative that best completes the statement or answers the question.
An egg falls from a bird's nest in a tree and feels no effects due to the air. As it falls,

A) only its momentum is conserved.
B) both its kinetic energy and its momentum are conserved.
C) both its mechanical energy and its momentum are conserved.
D) only its mechanical energy is conserved.
E) only its kinetic energy is conserved.

Question 41

Write the word or phrase that best completes each statement or answers the question.
A 14,000-kg boxcar is coasting at 1.50 m/s along a horizontal track when it suddenly hits and couples with a stationary 10,000-kg boxcar. What is the speed of the cars just after the collision?

Question 42

Choose the one alternative that best completes the statement or answers the question.
A 600-kg car makes a $90 ^ { \circ }$ turn. Its speed before the turn is 21.0 m/s and after the turn it is 24.0 m/s. What is the magnitude of the change in the car's momentum during the turn?

A) $22.2 \times 10 ^ { 3 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
B) $12.0 \times 10 ^ { 3 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $19.1 \times 10 ^ { 3 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $10.2 \times 10 ^ { 3 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
E) $9.55 \times 10 ^ { 3 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 43

Choose the one alternative that best completes the statement or answers the question.
A 1200-kg cannon suddenly fires a 100-kg cannonball at 35 m/s. What is the recoil speed of the cannon? Assume that frictional forces are negligible and the cannon is fired horizontally.

A) 35 m/s
B) 3.5 m/s
C) 2.9 m/s
D) 3.2 m/s

Question 44

Choose the one alternative that best completes the statement or answers the question.
A 0.10-kg ball, traveling horizontally at 25 m/s, strikes a wall and rebounds at 19 m/s. What is the magnitude of the change in the momentum of the ball during the rebound?

A) $5.4 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
B) $1.8 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $4.4 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $1.2 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
E) $72 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 45

Choose the one alternative that best completes the statement or answers the question.
A 1200-kg ore cart is rolling at 10.8 m/s across a flat friction-free surface. A crane suddenly drops 858 kg of ore vertically into the cart. How fast does the cart move just after being loaded with the ore?

A) 4.20 m/s
B) 3.80 m/s
C) 5.70 m/s
D) 6.30 m/s

Question 46

Write the word or phrase that best completes each statement or answers the question.
In a police ballistics test, 2.00-g bullet traveling at 700 m/s suddenly hits and becomes embedded in a stationary 5.00-kg wood block. What is the speed of the block immediately after the bullet has stopped moving relative to the block?

Question 47

Choose the one alternative that best completes the statement or answers the question.
A dinner plate falls vertically to the floor and breaks up into three pieces, which slide horizontally along the floor. Immediately after the impact, a 200-g piece moves along the +x -axis with a speed of 2.00 m/s, a 235-g piece moves along the +y -axis with a speed of 1.50 m/s. The third piece has a mass of 100 g. What is the speed of the third piece?

A) 2.57 m/s
B) 6.83 m/s
C) 5.33 m/s
D) 3.50 m/s
E) 2.51 m/s

Question 48

Choose the one alternative that best completes the statement or answers the question.
A firecracker breaks up into two pieces, one of which has a mass of 200 g and flies off along the +x -axis with a speed of 82.0 m/s. The second piece has a mass of 300 g and flies off along the +y -axis with a speed of 45.0 m/s. What is the total momentum of the two pieces?

A) $21.2 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s } \text { at } 56.3 ^ { \circ } \text { from the } + x \text {-axis }$
B) $21.2 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s } \text { at } 39.5 ^ { \circ } \text { from the } + x \text {-axis }$
C) $361 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s } \text { at } 56.3 ^ { \circ } \text { from the } + x \text {-axis }$
D) $361 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s } \text { at } 0.983 ^ { \circ } \text { from the } + x \text {-axis }$
E) $93.5 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s } \text { at } 28.8 ^ { \circ } \text { from the } + x \text {-axis }$

Question 49

Choose the one alternative that best completes the statement or answers the question.
Two ice skaters suddenly push off against one another starting from a stationary position. The 45-kg skater acquires a speed of 0.375 m/s relative to the ice. What speed does the 60-kg skater acquire relative to the ice?

A) 0.50 m/s
B) 0.38 m/s
C) 0.00 m/s
D) 0.28 m/s
E) 0.75 m/s

Question 50

Choose the one alternative that best completes the statement or answers the question.
A dinner plate falls vertically to the floor and breaks up into three pieces, which slide horizontally along the floor. Immediately after the impact, a 320-g piece moves along the +x -axis with a speed of 2.00 m/s and a 355-g piece moves along the +y -axis with a speed of 1.50 m/s. The third piece has a mass of 100 g. In what direction relative to the +x -axis does the third piece move?

A) $39.9 ^ { \circ } \text { from the } + x \text {-axis }$
B) $216.9 ^ { \circ } \text { from the } + x \text {-axis }$
C) $219.8 ^ { \circ } \text { from the } + x \text {-axis }$
D) $36.9 ^ { \circ } \text { from the } + x \text {-axis }$
E) $39.8 ^ { \circ } \text { from the } + x \text {-axis }$

Question 51

Write the word or phrase that best completes each statement or answers the question.
An empty train car of mass $2.0 \times 10 ^ { 4 }$ kg coasts along at 10 m/s. A 3000-kg boulder is suddenly dropped vertically into the car. Find the speed of the car immediately after the boulder is dropped in.

Question 52

Write the word or phrase that best completes each statement or answers the question.
Find the magnitude and direction of the net momentum of the system shown in the figure. Express the direction by giving the angle the net momentum makes with the +x -axis.

Question 53

Choose the one alternative that best completes the statement or answers the question.
Two astronauts, of masses 60 kg and 80 kg, are initially right next to each other and at rest in outer space. They suddenly push each other apart. How far has the heavier astronaut moved when the lighter astronaut has moved 12 m?

A) 7.0 m
B) 16 m
C) 21 m
D) 9.0 m
E) 12 m

Question 54

Choose the one alternative that best completes the statement or answers the question.
Two astronauts, of masses 60 kg and 80 kg, are initially right next to each other and at rest in outer space. They suddenly push each other apart. What is their separation after the heavier astronaut has moved 12 m?

A) 28 m
B) 24 m
C) 9.0 m
D) 16 m
E) 21 m

Question 55

Choose the one alternative that best completes the statement or answers the question.
A 328-kg car moving at 19.1 m/s in the +x direction hits from behind a second car moving at 13.0 m/s in the same direction. If the second car has a mass of 790 kg and a speed of 15.1 m/s right after the collision, what is the velocity of the first car after this sudden collision?

A) 14.0 m/s
B) 18.2 m/s
C) -14.0 m/s
D) 24.2 m/s

Question 56

Choose the one alternative that best completes the statement or answers the question.
Two air track carts move along an air track towards each other. Cart A has a mass of 450 g and moves toward the right with a speed of 0.850 m/s. Cart B has a mass of 300 g and moves toward the left with a speed of 1.12 m/s. What is the total momentum of the two-cart system?

A) 0.047 kg . m/s toward the right
B) 0.750 kg . m/s toward the right
C) 0.750 kg . m/s toward the left
D) 0.719 kg . m/s toward the right
E) 0.719 kg . m/s toward the left

Question 57

Choose the one alternative that best completes the statement or answers the question.
A 0.140-kg baseball is dropped and reaches a speed of 1.20 m/s just before it hits the ground and bounces. It rebounds with an upward velocity of 1.00 m/s. What is the change of the ball's momentum during the bounce?

A) 0.000 kg . m/s
B) 0.0280 kg . m/s upwards
C) 0.0280 kg . m/s downwards
D) 0.308 kg . m/s downwards
E) 0.308 kg . m/s upwards

Question 58

Choose the one alternative that best completes the statement or answers the question.
A 100-g ball falls from a window that is 12 m above ground level and experiences no significant air resistance as it falls. What is its momentum when it strikes the ground?

A) 3.3 kg . m/s
B) 4.8 kg . m/s
C) 1.5 kg . m/s
D) 2.4 kg . m/s
E) 1.8 kg . m/s

Question 59

Choose the one alternative that best completes the statement or answers the question.
In a police ballistics test, a 10.0-g bullet moving at 300 m/s is fired into a 1.00-kg block at rest. The bullet goes through the block almost instantaneously and emerges with 50.0% of its original speed. What is the speed of the block just after the bullet emerges?

A) 1.50 m/s
B) 273 m/s
C) 3.00 m/s
D) 2.97 m/s

Question 60

Write the word or phrase that best completes each statement or answers the question.
A 60-kg swimmer suddenly dives horizontally from a 150-kg raft with a speed of 1.5 m/s . The raft is initially at rest. What is the speed of the raft immediately after the diver jumps if the water has negligible effect on the raft?

Question 61

Choose the one alternative that best completes the statement or answers the question.
Astronaut Jennifer's lifeline to her spaceship comes loose and she finds herself stranded, "floating" 100 m from the mothership. She suddenly throws her 2.00-kg wrench at 20 m/s in a direction away from the ship. If she and her spacesuit have a combined mass of 200 kg, how long does it take her to coast back to her spaceship?

A) 500 s
B) 750 s
C) 1000 s
D) 2.50 min
E) 250 s

Question 62

Choose the one alternative that best completes the statement or answers the question.
A block of mass m=34 kg and speed V is behind a block of mass M=81 kg and speed of 0.50 m/s, as shown in the figure. The surface is frictionless and the blocks collide and couple. After the collision, the blocks have a common speed of 0.90 m/s. What is the magnitude of the impulse on the 34-kg block due to the collision?

A) $73 \mathrm {~N} \cdot \mathrm { s }$
B) $57 \mathrm {~N} \cdot \mathrm { s }$
C) $32 \mathrm {~N} \cdot \mathrm { s }$
D) $14 \mathrm {~N} \cdot \mathrm { s }$
E) $41 \mathrm {~N} \cdot \mathrm { s }$

Question 63

Write the word or phrase that best completes each statement or answers the question.
Jennifer hits a stationary 0.20-kg ball, and it leaves her racket at 40 m/s. Time-lapse
photography shows that the ball was in contact with the racket for 40 ms.
(a) What average force did the ball exert on the racket?
(b) What is the ratio of this force to the weight of the ball?

Question 64

Choose the one alternative that best completes the statement or answers the question.
A 14-cm diameter champagne bottle rests on its side on top of a frictionless horizontal table. Suddenly, the cork pops and the bottle slides backward, covering a distance of 22.0 cm in 0.44 s. If the mass of the bottle is 500 times the mass of the cork, find the distance from the original position that the cork will land on the table. Neglect air resistance and assume that the cork is very small compared to the bottle.

A) 8.5 cm
B) 3000 cm
C) 85 m
D) 60 m

Question 65

Choose the one alternative that best completes the statement or answers the question.
A very small 51-g steel ball is released from rest and falls vertically onto a steel plate. The ball strikes the plate and is in contact with it for 0.50 ms. The ball rebounds elastically and returns to its original height. The total time interval for a round trip is 3.00 s. What is the magnitude of the average force exerted on the ball by the plate during contact with the plate?

A) 2490 N
B) 1500 N
C) 3000 N
D) 2000 N
E) 3500 N

Question 66

Choose the one alternative that best completes the statement or answers the question.
A 0.140-kg baseball is thrown with a velocity of 27.1 m/s.It is struck by the bat with an average force of 5000 N, which results in a velocity of 37.0 m/s in the opposite direction from the original
Velocity. How long were the bat and ball in contact?

A) $3.07 \times 10 ^ { - 2 } \mathrm {~s}$
B) $1.79 \times 10 ^ { - 3 } \mathrm {~s}$
C) $4.30 \times 10 ^ { - 3 } \mathrm {~s}$
D) $1.28 \times 10 ^ { - 2 } \mathrm {~s}$

Question 67

Write the word or phrase that best completes each statement or answers the question.
A 475-gram ball is traveling horizontally at 12.0 m/s to the left when it is suddenly struck horizontally by a bat, causing it to reverse direction and initially travel at 8.50 m/s to the right. If the bat produced an average force of 1275 N on the ball, for how long (in milliseconds) was it in contact with the ball?

Question 68

Write the word or phrase that best completes each statement or answers the question.
A 0.17-kg baseball is thrown with a speed of 38 m/s and it is hit straight back toward the
pitcher with a speed of 62 m/s. What is the magnitude of the impulse exerted upon the ball
by the bat?

Question 69

Choose the one alternative that best completes the statement or answers the question.
A girl of mass 55 kg throws a ball of mass 0.80 kg against a wall. The ball strikes the wall horizontally with a speed of 25 m/s, and it bounces back with this same speed. The ball is in contact with the wall 0.050 s. What is the magnitude of the average force exerted on the wall by the ball?

A) 400 N
B) 13,750 N
C) 55,000 N
D) 800 N
E) 27,500 N

Question 70

Choose the one alternative that best completes the statement or answers the question.
A super dart of mass 20 g, traveling at 350 m/s, strikes a steel plate at an angle of $30 ^ { \circ }$ with the plane of the plate, as shown in the figure. It bounces off the plate at the same angle but at a speed of 320 m/s. What is the magnitude of the impulse that the plate gives to the bullet?

A) $4.3 \mathrm {~N} \cdot \mathrm { s }$
B) $300 \mathrm {~N} \cdot \mathrm { s }$
C) $0.30 \mathrm {~N} \cdot \mathrm { s }$
D) $6.7 \mathrm {~N} \cdot \mathrm { s }$
E) $0.52 \mathrm {~N} \cdot \mathrm { s }$

Question 71

Choose the one alternative that best completes the statement or answers the question.
A forklift pushes a 100-kg crate, starting from rest, with a horizontal force of magnitude F . The graph in the figure shows the x component of this force as a function of time. What is the instantaneous velocity of the crate at time t=10 s?

A) 25 cm/s
B) 0.00 cm/s
C) 75 cm/s
D) -75 cm/s
E) -25 cm/s

Question 72

Choose the one alternative that best completes the statement or answers the question.
A steady horizontal force lasting for 2.1 s gives a 1.25 kg object an acceleration of $3.2 \mathrm {~m} / \mathrm { s } ^ { 2 }$ on a frictionless table. What impulse does this force give to the object?

A) $2.6 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
B) $26 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $8.4 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $11 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 73

Choose the one alternative that best completes the statement or answers the question.
A golf ball of mass 0.050 kg is at rest on the tee. Just after being struck, it has a velocity of 102 m/s. If the club and ball were in contact for 0.81 ms, what is the average force exerted on the ball by the club?

A) 5.5 kN
B) 4.9 kN
C) 7.1 kN
D) 6.3 kN

Question 74

Write the word or phrase that best completes each statement or answers the question.
A batter applies an average force of 8000 N to a baseball for 1.1 ms. What is the magnitude
of the impulse delivered to the baseball by the bat?

Question 75

Choose the one alternative that best completes the statement or answers the question.
A 0.24 kg blob of clay is thrown at a wall with an initial horizontal velocity of 16 m/s. If the clay comes to a stop in 91 ms, what is the average horizontal force on the clay due to the wall?

A) 35 N
B) 42 N
C) 51 N
D) 26 N

Question 76

Choose the one alternative that best completes the statement or answers the question.
A golf club exerts an average horizontal force of 1000 N on a 0.045-kg golf ball that is initially at rest on the tee. The club is in contact with the ball for 1.8 ms. What is the speed of the golf ball just
As it leaves the tee?

A) 40 m/s
B) 45 m/s
C) 30 m/s
D) 35 m/s
E) 50 m/s

Question 77

Choose the one alternative that best completes the statement or answers the question.
A 0.140 kg baseball is thrown horizontally with a velocity of 28.9 m/s. It is struck with a constant horizontal force that lasts for 1.85 ms, which results in a velocity of 37.0 m/s in the opposite direction. What was the magnitude of the horizontal force?

A) 4.99 kN
B) 0.613 kN
C) 2.80 kN
D) 2.19 kN

Question 78

Choose the one alternative that best completes the statement or answers the question.
Calculate the impulse due to a force of 4.5 N that lasts for 1.4 s.

A) 6.9 kg· m/s
B) 5.0 kg· m/s
C) 6.3 kg· m/s
D) 5.7 kg· m/s

Question 79

Choose the one alternative that best completes the statement or answers the question.
The graph in the figure shows the x component F of the net force that acts for 10 s on a 100-kg crate. What is the change in the momentum of the crate during the 10 s that this force acts?

A) $25 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
B) $- 75 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
C) $- 100 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
D) $75 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$
E) $- 25 \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Question 80

Write the word or phrase that best completes each statement or answers the question.
A batter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the
ball leaves the bat at 40 m/s in the reverse of its original direction. The ball remains in
contact with the bat for 2.0 ms. What is the magnitude of the average force exerted by the
bat on the ball?