Physics Principles with Applications 7th Edition Giancoli By - Test Bank

Physics Principles with Applications 7th Edition Giancoli By – Test Bank

 

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Sample Questions Are Posted Below

 

Exam

 

Name___________________________________

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

1) A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a

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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?

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

 

2)	Which of the following quantities are units of momentum? (There could be more than one correct					2)
	choice.)			D) kg · m2/s2
	A) N · m	B) N · s	C) kg · s/m		E) kg · m/s
3)	A tiger is running in a straight line. If we double both the mass and speed of the tiger, the					3)
	magnitude of its momentum will increase by what factor?
	A) 2	B)   2	C) 16	D) 4	E) 8
4)	A very elastic rubber ball is dropped from a certain height and hits the floor with a downward					4)
	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.)

1. The ball had the same momentum just before and just after the bounce.
   1. The ball’s momentum was conserved during the bounce.
2. The magnitude of the ball’s momentum was the same just before and just after the bounce.
3. None of the above statements are correct.

 

5)	The momentum of an isolated system is conserved			5)
	A) in both elastic and inelastic collisions.
	B) only in elastic collisions.
	C) only in inelastic collisions.
6)	Two friends are standing on opposite ends of a canoe that is initially at rest with respect to a			6)
	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.
7)	You are standing on a skateboard, initially at rest. A friend throws a very heavy ball towards you.			7)
	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?

1. Catch the ball.
   1. Deflect the ball back.
2. Your final speed on the skateboard will be the same regardless whether you catch the ball or deflect the ball.

 

 

 

 

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8) A small car meshes with a large truck in a head-on collision. Which of the following statements

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concerning the magnitude of the momentum change during the collision is correct? (There could be more than one correct choice.)

1. The small car and the truck experience the same magnitude momentum change.
2. The magnitude of the momentum change experienced by each one is directly proportional to its mass.
3. The truck experiences the greater magnitude momentum change.
4. The small car experiences the greater magnitude momentum change.
5. The magnitude of the momentum change experienced by each one is inversely proportional to its mass.

 

9) A small car meshes with a large truck in a head-on collision. Which of the following statements

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concerning the momentum during the collision are correct? (There could be more than one correct choice.)

1. The momentum of the car is conserved.
2. The car and the truck must undergo the same change in speed.
3. The momentum of the car-truck system is conserved, but the momentum of each one separately is not conserved.
4. The momentum of the car and the momentum of the truck are each conserved.
5. The momentum of the truck is conserved.

 

10) Consider two less-than-desirable options. In the first you are driving 30 mph and crash head-on					10)
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) The force would be the same in both cases.
B) hitting the other car
C) hitting the brick wall
D) None of the above choices are correct.
11) A rocket explodes into two fragments, one 25 times heavier than the other. The magnitude of the					11)
momentum change of the lighter fragment is
A) 1/25 as great as the momentum change of the heavier fragment.
B) The same as the momentum change of the heavier fragment.
C) 5 times as great as the momentum change of the heavier fragment.
D) 1/4 as great as the momentum change of the heavier fragment.
E) 25 times as great as the momentum change of the heavier fragment.
12) Which of the following quantities are units of impulse? (There could be more than one correct					12)
choice.)	B) kg · m2/s2
A) N · m		C) N · s	D) kg · m/s	E) kg · s/m
13) Three cars, car X, car Y, and car Z, begin accelerating from rest at the same time. Car X is more					13)
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?

1. They all have the same amount of momentum.
2. Car X
3. Car Y
4. Car Z

 

 

 

 

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14) During World War I, Germany used a “Big Bertha” cannon to hurl shells into Paris 30 miles away.	14)
This gun also had a very long barrel. What was the reason for using a long barrel in these guns?

1. to exert a larger force on the shells
2. to allow the force of the expanding gases from the gunpowder to act for a longer time
3. to reduce frictional losses
4. to reduce the force exerted on the bullet due to the expanding gases from the gunpowder
5. to increase the force exerted on the bullet due to the expanding gases from the gunpowder

 

15)	In a collision between two unequal masses, which mass receives a greater magnitude impulse?	15)
	A) the smaller mass
	B) the larger mass
	C) They receive equal impulses.
16)	Identical forces act for the same length of time on two different objects. The magnitude of the	16)
	change in momentum of the lighter object is

1. exactly equal to the magnitude of the change in momentum of the larger mass.
3. larger than the magnitude of the change in momentum of the larger mass.
4. smaller than the magnitude of the change in momentum of the larger mass, but not zero.
5. There is not enough information to answer the question.

 

17) A very light ping-pong ball moving east at a speed of 4 m/s collides with a very heavy stationary	17)
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) Neither; both experienced the same magnitude impulse.
B) the bowling ball
C) the Ping-Pong ball
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.
18) A small car meshes with a large truck in a head-on collision. Which of the following statements	18)
concerning the magnitude of the average force during the collision is correct?
A) The force experienced by each one is directly proportional to its mass.
B) The force experienced by each one is inversely proportional to its mass.
C) The truck experiences the greater average force.
D) The small car experiences the greater average force.
E) The small car and the truck experience the same average force.
19) In an inelastic collision involving an isolated system, the final total momentum is	19)
A) more than the initial momentum.
B) exactly the same as the initial momentum.
C) less than the initial momentum.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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20) A 5-kg ball collides inelastically head-on with a 10-kg ball, which is initially stationary. Which of	20)
the following statements is true? (There could be more than one correct choice.)

1. The magnitude of the change of velocity the 5-kg ball experiences is less than that of the 10-kg ball.

 

1. The magnitude of the change of velocity the 5-kg ball experiences is greater than that of the 10-kg ball.
2. 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.
3. The magnitude of the change of velocity the 5-kg ball experiences is equal to that of the 10-kg ball.
4. Both balls lose all their momentum since the collision is inelastic.

 

21)	In a game of pool, the white cue ball hits the #5 ball and stops, while the #5 ball moves away with			21)
	the same velocity as the cue ball had originally. Both balls have the same mass. This type of
	collision is
	A) elastic.	B) somewhat inelastic.	C) completely inelastic.
22)	In the figure, determine the character of the collision. The masses of the blocks, and the velocities			22)
	before and after, are shown. The collision is

 

 

 

 

 

1. completely inelastic.
2. partially inelastic.
3. perfectly elastic.
4. characterized by an increase in kinetic energy.
5. not possible because momentum is not conserved.

 

23) In the figure showing an isolated system, determine the character of the collision. The masses of the 23) blocks, and the velocities before and after, are shown. The collision is

 

 

 

 

 

 

 

1. perfectly elastic.
2. completely inelastic.
3. partially inelastic.
4. characterized by an increase in kinetic energy.
5. not possible because momentum is not conserved.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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24) In the figure, determine the character of the collision. The masses of the blocks, and the velocities	24)
before and after, are shown. The collision is

 

 

 

 

 

 

1. A) partially inelastic.
2. B) completely inelastic.
3. C) perfectly elastic.
4. D) characterized by an increase in kinetic energy.

E) not possible because momentum is not conserved.
25) A 2.0-kg ball moving eastward at 3.0 m/s suddenly collides with and sticks to a 4.0 -kg ball moving	25)
northward at 2.0 m/s. What is the magnitude of the momentum of this system just after the
collision?
A) 2.0 kg · m/s
B) 8.0 kg · m/s
C) 6.0 kg · m/s
D) 10 kg · m/s
E) 14 kg · m/s
26) An egg falls from a bird’s nest in a tree and feels no effects due to the air. As it falls,	26)
A) only its momentum is conserved.
B) both its mechanical energy and its momentum are conserved.
C) only its kinetic energy is conserved.
D) both its kinetic energy and its momentum are conserved.
E) only its mechanical energy is conserved.
27) If a quantity you calculated had units of kg · m/s, what type of quantity could it be? (There could	27)
be more than one correct choice.)
A) kinetic energy
B) impulse
C) momentum
D) work
E) force
28) A railroad car collides with and sticks to an identical railroad car that is initially at rest. After the	28)
collision, the kinetic energy of the system
A) is half as much as before.

1. B) is one quarter as much as before.
2. C) is one fourth as much as before.
3. D) is the same as before.
4. E) is one third as much as before.

 

 

 

 

 

 

 

 

 

 

 

 

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29) A rubber ball bounces off of a wall with an initial speed v and reverses its direction so its speed is v	29)
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 kinetic energy of the ball
C) the momentum of the ball
D) None of the above quantities are conserved.
30) On a horizontal frictionless air table, a puck runs into an ideal horizontal spring that is fastened to	30)
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) only the kinetic energy of the puck
C) the momentum and the mechanical energy of the puck
D) only the mechanical energy (kinetic plus potential) of the puck
E) the momentum and the kinetic energy of the puck
31) Two objects of different mass have equal, non-zero kinetic energies. Which object has the greater	31)
magnitude momentum?
A) the lighter object
B) the heavier object
C) They both have the same magnitude momentum.

 

32) Two objects of different masses have momentum of equal, non -zero magnitude. Which object has 32) more kinetic energy?

 

1. the lighter object
2. the heavier object
3. They both have the same kinetic energy.

 

33)	If you want to double the kinetic energy of a gas molecule, by what factor must you increase its					33)
	momentum?
	A) 16	B)2  2	C) 4	D) 2	E)   2
34)	If you want to double the momentum of a gas molecule, by what factor must you increase its					34)
	kinetic energy?
	A)2 2	B) 16	C)   2	D) 2	E) 4
35)	A firecracker explodes in midair and breaks up into many fragments. Which of the following					35)
	statements are true regarding conditions immediately before and immediately after the explosion:

1. The total momentum of the fragments is equal to the original momentum of the firecracker.
2. The total kinetic energy of the fragments is equal to the original kinetic energy of the firecracker.
3. A) Statement I only B) Statement II only
4. C) Both Statement I and Statement II D) Neither statement is true.

 

36) There must be equal amounts of mass on both sides of the center of mass (or center of gravity) of a  36)

system.

1. A) True B) False

 

 

 

 

 

 

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SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

37) What is the magnitude of the momentum of a 0.140 kg baseball traveling at 45.0 m/s?

37)

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

38)	A 0.14-kg baseball is dropped from rest from a height of 2.0 m above the ground. What is the	38)
	magnitude of its momentum just before it hits the ground if we neglect air resistance?
	A) 0.44 kg · m/s
	B) 0.88 kg · m/s
	C) 0.28 kg · m/s
	D) 1.4 kg · m/s
	E) 0.62 kg · m/s
39)	Three objects are moving along a straight line as shown in the figure. Taking the positive direction	39)
	to be to the right, what is the total momentum of this system?

 

 

 

 

14. +0 kg · m/s
15. +106 kg m/s
16. -0 kg · m/s
17. 00 kg · m/s
18. -106 kg m/s

 

40) A 0.330-kg volleyball is thrown vertically downward with a speed of 0.150 m/s in a place where g

40)

• 81 m/s². It takes it 0.0655 s to reach the ground. What is the magnitude of its momentum just before it hits the ground?

 

1. 212 kg · m/s

 

1. 0216 kg · m/s
2. 163 kg · m/s
3. 262 kg · m/s
4. 0418 kg · m/s

 

41) Two air track carts move along an air track towards each other. Cart A has a mass of 450 g and	41)
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) 0.719 kg · m/s toward the right
B) 0.047 kg · m/s toward the right
C) 0.750 kg · m/s toward the right
D) 0.750 kg · m/s toward the left
E) 0.719 kg · m/s toward the left
42) A 100-g ball falls from a window that is 12 m above ground level and experiences no significant	42)
air resistance as it falls. What is its momentum when it strikes the ground?

1. A) 1.8 kg m/s
2. B) 2.4 kg m/s
3. C) 4.8 kg m/s
4. D) 3.3 kg m/s
5. E) 1.5 kg m/s

 

 

 

 

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43) A 0.140-kg baseball is dropped and reaches a speed of 1.20 m/s just before it hits the ground and	43)
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) 0.308 kg · m/s downwards
B) 0.000 kg · m/s
C) 0.308 kg · m/s upwards
D) 0.0280 kg · m/s downwards
E) 0.0280 kg · m/s upwards
44) A firecracker breaks up into two pieces, one of which has a mass of 200 g and flies off along the	44)
+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 kg · m/s at 39.5° from the +x-axis

21. B) 21.2 kg m/s at 56.3° from the +x-axis
22. C) 361 kg m/s at 56.3° from the +x-axis
23. D) 93.5 kg m/s at 28.8° from the +x-axis
24. E) 361 kg m/s at 0.983° from the +x-axis

 

SHORT ANSWER. 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. 45) Express the direction by giving the angle the net momentum makes with the +x–

 

 

 

 

 

 

 

 

 

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

46)	A 600-kg car makes a 90° turn. Its speed before the turn is 21.0 m/s and after the turn it is 24.0 m/s.		46)
	What is the magnitude of the change in the car’s momentum during the turn?
	A) 12.0 × 103 kg·m/s
	B) 22.2	× 103 kg·m/s
	C) 10.2	× 103 kg·m/s
	D) 19.1	× 103 kg·m/s
	E) 9.55	× 103 kg·m/s
47)	A 0.10-kg ball, traveling horizontally at 25 m/s, strikes a wall and rebounds at 19 m/s. What is the		47)
	magnitude of the change in the momentum of the ball during the rebound?

4. A) 4.4 kg m/s
5. B) 5.4 kg m/s
6. C) 1.8 kg m/s
7. D) 72 kg m/s
8. E) 1.2 kg m/s

 

 

 

 

 

 

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SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

48)	A 60-kg swimmer suddenly dives horizontally from a 150-kg raft with a speed of 1.5 m/s.	48)
	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?
49)	A 14,000-kg boxcar is coasting at 1.50 m/s along a horizontal track when it suddenly hits	49)
	and couples with a stationary 10,000-kg boxcar. What is the speed of the cars just after the
	collision?
50)	In a police ballistics test, 2.00-g bullet traveling at 700 m/s suddenly hits and becomes	50)
	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?

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

51)	A 328-kg car moving at 19.1 m/s in the +x direction hits from behind a second car moving at				51)
	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) 24.2 m/s	D) 14.0 m/s
52)	A 1200-kg ore cart is rolling at 10.8 m/s across a flat friction-free surface. A crane suddenly drops				52)
	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

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

53) An empty train car of mass 2.0 x 104 kg coasts along at 10 m/s. A 3000-kg boulder is

53)

suddenly dropped vertically into the car. Find the speed of the car immediately after the boulder is dropped in.

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

54)	Two ice skaters suddenly push off against one another starting from a stationary position. The					54)
	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) 0.75 m/s	B) 0.50 m/s	C) 0.00 m/s	D) 0.28 m/s	E) 0.38 m/s
55)	A 1200-kg cannon suddenly fires a 100-kg cannonball at 35 m/s.What is the recoil speed of the					55)
	cannon? Assume that frictional forces are negligible and the cannon is fired horizontally.
	A) 2.9 m/s	B) 3.2 m/s	C) 3.5 m/s		D) 35 m/s
56)	A dinner plate falls vertically to the floor and breaks up into three pieces, which slide horizontally					56)
	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) 2.51 m/s	C) 5.33 m/s	D) 3.50 m/s	E) 6.83 m/s

 

 

 

 

 

 

 

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57) A dinner plate falls vertically to the floor and breaks up into three pieces, which slide horizontally					57)
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) 39.8° from the +x-axis
B) 219.8° from the +x-axis
C) 216.9° from the +x-axis
D) 36.9° from the +x-axis
E) 39.9° from the +x-axis
58) 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					58)
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) 2.97 m/s	B) 1.50 m/s		C) 3.00 m/s	D) 273 m/s
59) Two astronauts, of masses 60 kg and 80 kg, are initially right next to each other and at rest in outer					59)
space. They suddenly push each other apart. What is their separation after the heavier astronaut
has moved 12 m?
A) 16 m	B) 24 m	C) 21 m	D) 9.0 m	E) 28 m
60) Two astronauts, of masses 60 kg and 80 kg, are initially right next to each other and at rest in outer					60)
space. They suddenly push each other apart. How far has the heavier astronaut moved when the
lighter astronaut has moved 12 m?
A) 21 m	B) 16 m	C) 7.0 m	D) 9.0 m	E) 12 m
61) Astronaut Jennifer’s lifeline to her spaceship comes loose and she finds herself stranded, “floating”					61)
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) 2.50 min	C) 1000 s	D) 750 s	E) 250 s
62) A 14-cm diameter champagne bottle rests on its side on top of a frictionless horizontal table.					62)
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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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63) The graph in the figure shows the x component F of the net force that acts for 10 s on a 100-kg	63)
crate. What is the change in the momentum of the crate during the 10 s that this force acts?

 

 

 

 

 

 

 

 

1. A) -75 kg m/s
2. B) 25 kg m/s
3. C) 75 kg m/s
4. D) -100 kg m/s

E) -25 kg · m/s
64) A forklift pushes a 100-kg crate, starting from rest, with a horizontal force of magnitude F. The	64)
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?

 

 

 

 

 

 

 

 

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

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

65)	A batter applies an average force of 8000 N to a baseball for 1.1 ms. What is the magnitude	65)
	of the impulse delivered to the baseball by the bat?
66)	A batter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the	66)
	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?
67)	Jennifer hits a stationary 0.20-kg ball, and it leaves her racket at 40 m/s. Time-lapse	67)
	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?
68)	A 0.17-kg baseball is thrown with a speed of 38 m/s and it is hit straight back toward the	68)
	pitcher with a speed of 62 m/s. What is the magnitude of the impulse exerted upon the ball
	by the bat?

 

 

 

 

 

 

 

 

 

 

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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

69) A super dart of mass 20 g, traveling at 350 m/s, strikes a steel plate at an angle of 30° with the plane 69) 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) 300 N · s	B) 0.30 N · s	C) 0.52 N · s		D) 6.7 N · s	E) 4.3 N · s
70)	A golf club exerts an average horizontal force of 1000 N on a 0.045-kg golf ball that is initially at						70)
	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) 45 m/s	B) 30 m/s	C) 40 m/s		D) 35 m/s	E) 50 m/s
71)	A 0.140-kg baseball is thrown with a velocity of 27.1 m/s.It is struck by the bat with an average						71)
	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) 1.28 × 10–2 s	B) 4.30 × 10–3 s		C) 3.07 × 10–2 s		D) 1.79 × 10–3 s
72)	Calculate the impulse due to a force of 4.5 N that lasts for 1.4 s.						72)
	A) 6.9 kg· m/s	B) 5.7 kg· m/s		C) 5.0 kg· m/s		D) 6.3 kg· m/s
73)	A girl of mass 55 kg throws a ball of mass 0.80 kg against a wall. The ball strikes the wall						73)
	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) 27,500 N		D) 800 N	E) 55,000 N

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

74) A 475-gram ball is traveling horizontally at 12.0 m/s to the left when it is suddenly struck

74)

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?

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

75) A 0.140 kg baseball is thrown horizontally with a velocity of 28.9 m/s. It is struck with a constant				75)
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) 2.80 kN	B) 0.613 kN	C) 4.99 kN	D) 2.19 kN

 

 

 

 

 

 

 

12

 

76)	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.				76)
	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
77)	A 0.24 kg blob of clay is thrown at a wall with an initial horizontal velocity of 16 m/s. If the clay				77)
	comes to a stop in 91 ms, what is the average horizontal force on the clay due to the wall?
	A) 51N	B)35N	C) 26N	D)42N
78)	A steady horizontal force lasting for 2.1 s gives a 1.25 kg object an acceleration of 3.2 m/s2 on a				78)
	frictionless table. What impulse does this force give to the object?
	A) 11 kg · m/s	B) 26 kg · m/s	C) 8.4 kg · m/s	D) 2.6 kg · m/s
79)	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,				79)
	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 N · s	B) 41 N · s	C) 57 N · s	D) 14 N · s	E) 32 N · s
80)	A very small 51-g steel ball is released from rest and falls vertically onto a steel plate. The ball					80)
	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) 1500 N	B) 2000 N	C) 3000 N	D) 3500 N	E) 2490 N
81)	A 0.140-kg baseball is dropped from rest. It has a speed of 1.20 m/s just before it hits the ground,					81)
	and it rebounds with an upward speed of 1.00 m/s. The ball is in contact with the ground for
	0.0140 s. What is the average force exerted by the ground on the ball during the time of contact?

22. 0 N downwards
23. 0 N upwards
24. 00 N upwards
25. 00 N downwards
26. 00 N

 

82) A batter hits a foul ball. The 0.14-kg baseball that was approaching him at 40 m/s leaves the bat at					82)
30 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) 3.5 N · s	B) 7.0 N · s	C) 5.6 N · s	D) 1.4 N · s	E) 9.8 N · s

 

 

 

 

 

 

 

 

 

 

 

 

 

 

13

 

83) A block of mass m = 5.6 kg, moving on a frictionless surface with a velocity of vi = 6.5 m/s to the

83)

right, collides with a block of mass M at rest, as shown in the figure. After the collision, the 5.6-kg block recoils with a velocity of v_f = 0.70 m/s to the left. If the blocks are in contact for 0.20 s, what is the magnitude of the average force on the 5.6-kg block, while the two blocks are in contact?

 

 

 

 

 

1. A) 202N B)192N C)0N                             D)0N                              E)182N

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

84) A force of 5.3 N is needed to hold on to an umbrella in a strong wind. If the air molecules

84)

each have a mass of 4.7 ×10^{– 26} kg, and each one strikes the umbrella (without rebounding) with a speed of 2.0 m/s in the same direction, how many atoms strike the umbrella each second? Assume that the wind blows horizontally so that the gravity can be neglected.

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

85) A fire hose is turned on the door of a burning building in order to knock the door down. This				85)
requires a force of 1000 N. If the hose delivers 40 kg of water per second, what is the minimum
velocity of the stream needed to knock down the door, assuming the water doesn’t bounce back?
A) 30 m/s	B) 25 m/s	C) 15 m/s	D) 20 m/s

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

86) A 2200-kg auto moving northward at 12.0 m/s runs into a 3800-kg truck which is also

86)

moving northward, but at 5.00 m/s. If the vehicles lock bumpers, how fast are they moving just after the collision?

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

87)	A 1200-kg car moving at 15.6 m/s suddenly collides with a stationary car of mass 1500 kg. If the				87)
	two vehicles lock together, what is their combined velocity immediately after the collision?
	A) 6.9 m/s	B) 12.1 m/s	C) 8.6 m/s	D) 5.5 m/s
88)	A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s. It suddenly collides directly				88)
	with a stationary seal of mass 200 kg. The seal grabs onto the whale and holds fast. What is the
	momentum of these two sea creatures just after their collision? You can neglect any drag effects of
	the water during the collision.

1. 6000 kg m/s

 

1. 1200 kg m/s
2. 00 kg · m/s
3. 2000 kg m/s
4. 7200 kg m/s

 

 

 

 

 

 

 

 

 

14

 

89)	A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s. It suddenly collides directly						89)
	with a stationary seal of mass 200 kg. The seal grabs onto the whale and holds fast. What is the
	speed of these two sea creatures just after their collision? You can neglect any drag effects of the
	water during the collision.
	A)	4.0 m/s	B) 0.00 m/s	C) 3.0 m/s	D) 5.0 m/s	E) 6.0 m/s
90)	A 2.0-kg mass moving at 5.0 m/s suddenly collides head-on with a 3.0-kg mass at rest. If the						90)
	collision is perfectly inelastic, what is the speed of the masses just after the collision?
	A)	2.0 m/s			B) 2.5 m/s
	C)	10 m/s		D) 0 m/s, since the collision is inelastic
91)	A block of mass m = 4.4 kg, moving on frictionless surface with a speed vi = 9.2 m/s, makes a						91)
	sudden perfectly elastic collision with a second block of mass M, as shown in the figure. The
	second block is originally at rest. Just after the collision, the 4.4-kg block recoils with a speed of
	vf = 2.5 m/s. What is the mass M of the second block?

 

 

 

 

A) 0 kg	B) 0 kg	C) 0 kg	D) 7.7 kg	E) 0 kg
92) A block of mass m = 3.6 kg, moving on a frictionless surface with a speed vi = 9.3 m/s, makes a					92)

sudden perfectly elastic collision with a stationary block of mass M, as shown in the figure. Just after the collision, the 3.6-kg block recoils with a speed of v_f = 2.7 m/s.What is the speed V of the other block?

 

 

 

 

 

	A) 6.6 m/s	B) 12.0 m/s	C) 8.0 m/s	D) 10.7 m/s	E) 9.3 m/s
93)	A 320-g air track cart traveling at 1.25 m/s suddenly collides elastically with a stationary 270-g					93)
	cart. What is the speed of the 270-g cart just after the collision?
	A) 0.106 m/s	B) 2.72 m/s	C) 1.36 m/s	D) 0.678 m/s	E) 1.14 m/s
94)	A 320-g air track cart traveling at 1.25 m/s suddenly collides elastically with a stationary 270-g					94)
	cart. What is the speed of the 320-g cart just after the collision?
	A) 0.11 m/s	B) 1.4 m/s	C) 0.21 m/s	D) 1.1 m/s	E) 0.68 m/s
95)	A 550-g ball traveling at 8.0 m/s undergoes a sudden head-on elastic collision with a 250-g ball					95)
	traveling toward it also at 8.0 m/s. What is the speed of the 250-g mass just after the collision?
	A) 0 m/s	B) 14 m/s	C) 4.0 m/s	D) 15 m/s	E) 8.0 m/s

 

 

 

 

 

 

 

 

 

 

 

 

15

 

96) A 340-g air track cart traveling at 1.25 m/s suddenly collides elastically with a stationary 300-g				96)
cart. What is the speed of the 300-g cart just after the collision?
A) 0.664 m/s
B) 0.0781 m/s
C) 0.625 m/s
D) 1.25 m/s
E) 1.33 m/s
97) A proton of mass m is at rest when it is suddenly struck head-on by an alpha particle (which				97)
consists of 2 protons and 2 neutrons) moving at speed v. If the collision is perfectly elastic, what
speed will the alpha particle have after the collision? (Assume the neutron’s mass is equal to the
proton’s mass.)
A) 2v/3	B) 3v/5	C) zero	D) 5v/3
98) A 50-g ball moving at 10 m/s in the +x direction suddenly collides head-on with a stationary ball				98)
of mass 100 g. If the collision is perfectly elastic, what is the velocity of each ball immediately after
the collision?
A) -3.3 m/s, +6.7 m/s		B) +6.7 m/s, -3.3 m/s
C) -6.7 m/s, +3.3 m/s		D) +3.3 m/s, -6.7 m/s

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

99)	In a perfectly elastic collision, a 400-g ball moving toward the east at 3.7 m/s suddenly	99)
	collides head-on with a 200 g ball sitting at rest.
	(a) Determine the velocity of the first ball just after the collision.
	(b) Determine the velocity of the second ball just after the collision.
	(c) Is kinetic energy conserved in this collision? How do you know?
100)	An 80-kg man is skating northward and happens to suddenly collide with a 20-kg boy	100)
	who is ice skating toward the east. Immediately after the collision, the man and boy are
	seen to be moving together at 2.5 m/s in a direction 60° north of east. How fast was the
	boy moving just before the collision?
101)	A car (of mass 1500 kg) and a small truck (of mass 2000 kg) collide suddenly at right	101)
	angles at an icy intersection. The car was originally traveling eastward at 20.0 m/s and the
	truck was traveling northward at 20.0 m/s just before the collision took place. What is the
	speed of the combined wreck just after the collision if the vehicles become enmeshed?

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

102) Two vehicles approach a right angle intersection and then suddenly collide. After the collision,

102)

they become entangled. If their mass ratios were 1:4 and their respective speeds as they approached the intersection were both 13 m/s, find the magnitude and direction of the final velocity of the wreck.

1. A) 16 m/s at 14° with respect to the original direction of the lighter car
2. B) 11 m/s at 14° with respect to the original direction of the lighter car
3. C) 26 m/s at 76° with respect to the original direction of the lighter car
4. D) 16 m/s at 76° with respect to the original direction of the lighter car
5. E) 11 m/s at 76° with respect to the original direction of the lighter car

 

 

 

 

 

 

16

 

103)	A car heading north suddenly collides at an intersection with a truck of the same mass heading					103)
	east. If they lock together and travel at 28 m/s at 15° north of east just after the collision, how fast
	was the car initially traveling?
	A) 28 m/s	B) 14 m/s	C) 7 m/s		D) 11 m/s
104)	A puck with a mass m1 = 50 g moving at 1.0 m/s approaches a stationary puck with a mass m2 =					104)
	100 g on a frictionless air table, and they undergo a sudden two-dimensional elastic collision. After
	the collision, both pucks have identical speeds, but travel in different directions. What is the angle
	between the original and final paths of puck with mass m1?
	A) 60°	B) 150°	C) 90°	D) 120°	E) 30°
105)	A 900-kg car traveling east at 15.0 m/s suddenly collides with a 750-kg car traveling north at 20.0					105)
	m/s. The cars stick together after the collision. What is the speed of the wreckage just after the
	collision?
	A) 35.0 m/s	B) 12.2 m/s	C) 25.0 m/s	D) 17.3 m/s	E) 6.10 m/s
106)	A 900-kg car traveling east at 15.0 m/s suddenly collides with a 750-kg car traveling north at 20.0					106)
	m/s. The cars stick together after the collision. In what direction does the wreckage move just after
	the collision?

45. 0° N of E
46. 1° N of E
47. 0° N of E
48. 9° N of E
49. 0° N of E

 

107)	A 900-kg car traveling 30.0° south of east at 12.0 m/s suddenly collides with a 750-kg car traveling					107)
	north at 17.0 m/s. The cars stick together after colliding. What is the speed of the wreckage just
	after the collision?
	A) 25.0 m/s	B) 12.2 m/s	C) 17.3 m/s	D) 20.4 m/s	E) 7.21 m/s
108)	A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000 -kg car traveling					108)
	at 60 km/h toward the south. The two cars stick together after the collision. What is the speed of
	the cars after collision?
	A) 14 m/s	B) 22 m/s	C) 8.3 m/s		D) 17 m/s
109)	A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000 -kg car traveling					109)
	at 60 km/h toward the south. The two cars stick together after the collision. What is the direction of
	motion of the cars after collision?
	A) 53.1° E of S	B) 53.1° S of E	C) 36.9° E of S		D) 36.9° S of E
110)	Two dogs, Rover and Fido, run on a level frictionless surface. Rover runs eastward with a					110)
	momentum of 24 kg . m/s, and Fido runs northward with momentum 10 kg . m/s. They make a
	sudden perfectly inelastic collision. What is the magnitude of their combined momentum after the
	collision?

1. 34 kg . m/s
2. 14 kg . m/s
3. 26 kg . m/s
4. It cannot be determined without knowing the masses and velocities of the dogs.

 

 

 

 

 

17

 

111) A 0.140-kg baseball is dropped from rest from a height of 2.20 m above the ground and

111)

experiences negligible air resistance as it falls. It rebounds to a height of 1.60 m. What change in the ball’s momentum occurs as it rebounds from the ground?

1. A) 0.117 kg m/s upwards
2. B) 0.350 kg m/s downwards
3. C) 0.117 kg m/s downwards
4. D) 0.350 kg m/s upwards
5. E) 1.70 kg m/s upwards

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

112) A 0.32-kg ball is moving horizontally at 30 m/s just before suddenly bouncing off a wall

112)

Just after the bounce, it is moving horizontally at 25 m/s but in the opposite direction.

(a) What is the magnitude of the change in momentum of the ball during the bounce?

(b) What percentage of the ball’s original kinetic energy was lost in the collision?

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

113)	In a police ballistics test, a 2.00-g bullet suddenly hits and becomes embedded in a 5.00-kg wood					113)
	block which is hanging from a 1.20-m long string. This causes the block to swing through an arc of
	3.50°. What was the speed of the bullet just before it hit the block?
	A) 789 m/s	B) 524 m/s	C) 262 m/s	D) 16.7 m/s	E) 25.3 m/s
114)	A block of mass m = 9.0 kg and speed V and is behind a block of mass M = 27 kg and speed of					114)
	0.50 m/s, as shown int the figure. The surface is frictionless, and the blocks suddenly collide and
	couple. After the collision, the blocks have a common speed of 0.90 m/s. How much kinetic energy
	of the blocks is lost due to the collision?

 

 

 

 

A) 4.6 J	B) 2.0 J	C)11J	D) 8.6 J	E)31J
115) As shown in the figure, a bullet of mass 0.010 kg moving horizontally suddenly strikes a block of					115)

wood of mass 1.5 kg that is suspended as a pendulum. The bullet lodges in the wood, and together they swing upward a vertical distance of 0.40 m. The length of the string is 2.0 m. What was the speed of the bullet just before it struck the wooden block?

 

 

 

 

 

 

 

 

 

 

 

1. A) 420 m/s B) 650 m/s C) 250 m/s                  D) 67 m/s                      E) 370 m/s

 

 

 

 

 

 

 

 

 

18

 

116) An 8.0-g bullet is suddenly shot into a 4.0-kg block that is at rest on a frictionless horizontal

116)

surface, as shown in the figure. The bullet remains lodged in the block. The block then moves against a spring and compresses it by 3.7 cm. The force constant (spring constant) of the spring is 2500 N/m. What was the initial speed v of the bullet?

 

 

 

 

A) 520 m/s	B) 440 m/s	C) 500 m/s	D) 480 m/s	E) 460 m/s
117) An 8.0-g bullet is suddenly shot into a 4.0-kg block, at rest on a frictionless horizontal surface, as					117)

shown in the figure. The bullet remains lodged in the block. The block then moves against a spring and compresses it by 8.9 cm. The force constant (spring constant) of the spring is 1400 N/m. What is the magnitude of the impulse on the block (including the bullet inside) due to the spring during the entire time interval during which the block compresses the spring?

 

 

 

 

6. A) 12 N s B) 6.7 N · s C) 8.3 N · s                  D) 10 N · s                    E) 13 N · s

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

118) In a police rifle test, a 15-g bullet traveling 213 m/s in a vertical direction suddenly buries

118)

itself in a 2.4-kg block of wood at rest directly above it. As a result, the bullet-block combination moves vertically upward.

(a) Determine the velocity of the bullet-block combination just after the impact. (b) Determine the maximum height reached by the bullet/block combination. (c) Is kinetic energy conserved in this collision?

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

119)	In a certain nuclear reactor, neutrons suddenly collide with deuterons, which have twice the mass					119)
	of neutrons. In a head-on elastic collision with a stationary deuteron, what fraction of the initial
	kinetic energy of a neutron is transferred to the deuteron?
	A) 1/3	B) 5/6	C) 8/9	D) 3/4	E) 1/2
120)	In a certain nuclear reactor, neutrons suddenly collide with carbon nuclei, which have 12 times the					120)
	mass of neutrons. In a head-on elastic collision with a stationary carbon nucleus, what fraction of
	its initial speed does the neutron have after the collision?
	A) 10/13	B) 1/12	C) 11/13	D) 11/12	E) 5/6
121)	An object initially at rest suddenly explodes in two fragments of masses 2.6 kg and 3.3 kg that					121)
	move in opposite directions. If the speed of the first fragment is 3.6 m/s, find the internal energy of
	the explosion.
	A) 30 kJ	B) 38 kJ	C) 30J		D)38J

 

 

 

 

 

 

 

 

 

 

 

19

 

122) Two simple pendulums of equal length l = 0.45 m are suspended from the same point. The				122)
pendulum bobs are small solid steel spheres. The first bob is drawn back to make a 35° angle with
the vertical, while the other one is left hanging at rest. If the first bob has a mass of 0.25 kg and the
second has a mass of 0.54 kg, how high will the second bob rise above its initial position when
struck elastically by the first bob after it is released?
A) 3.3 cm	B) 3.9 cm	C) 2.7 cm	D) 4.4 cm

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

123) On a frictionless horizontal surface, a 1.50-kg mass traveling at 3.50 m/s suddenly collides

123)

with and sticks to a 3.00-kg mass that is initially at rest, as shown in the figure. This system then runs into an ideal spring of force constant (spring constant) 50.0 N/cm. (a) What will be the maximum compression distance of the spring?

(b) How much mechanical energy is lost during this process? During which parts of the process (the collision and compression of the spring) is this energy lost?

 

 

 

 

 

 

 

 

124) A baseball pitcher is employing a ballistic pendulum to determine the speed of his fastball. 124) A 3.3-kg lump of clay is suspended from a cord 2.0 m long. When the pitcher throws his fastball aimed directly at the clay, the ball suddenly becomes embedded in the clay and

 

the two swing up to a maximum height of 0.080 m. If the mass of the baseball is 0.21 kg, find the speed of the pitched ball.

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

125) A 1200-kg pick-up truck traveling south at 15 m/s suddenly collides with a 750-kg car that is					125)
traveling east. The two vehicles stick together and slide along the road after colliding. A highway
patrol officer investigating the accident determines that the final position of the wreckage after the
collision is 25 m, at an angle of 50° south of east, from the point of impact. She also determines that
the coefficient of kinetic friction between the tires and the road at that location was 0.40. What was
the speed of the car just before the collision?
A) 23 m/s	B) 20 m/s	C) 17 m/s	D) 4.8 m/s	E) 14 m/s

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20

 

126) In the figure, four point masses are placed as shown. Assume that all the numbers in the figure are 126) accurate to two significant figures. What are the x and y coordinates of the center of mass (or center

 

of gravity) of this arrangement?

 

 

 

 

 

 

 

 

 

 

 

2. (2.2 m, 2.6 m)
3. (2.3 m, 2.8 m)
4. (2.3 m, 2.7 m)
5. (2.3 m, 2.6 m)
6. (2.2 m, 2.7 m)

 

127) As shown in the figure, a 60-cm length of uniform wire, of mass 60 g, is bent into a right triangle.	127)
What are the x and y coordinates of the center of mass (or center of gravity) of this triangle?

 

 

 

 

 

 

 

9. (9.0 cm, 4.0 cm)
10. (10 cm, 3.0 cm)
11. (8.0 cm, 5.0 cm)
12. (10 cm, 5.0 cm)
13. (8.0 cm, 3.0 cm)

 

128)	A 60.0-kg man stands at one end of a 20.0-kg uniform 10.0-m long board. How far from the man					128)
	is the center of mass (or center of gravity) of the man-board system?
	A) 5.00 m	B) 9.00 m	C) 1.25 m	D) 7.50 m	E) 2.50 m
129)	A 2.0-m rope is lying on a table. You pick up one end and start raising it vertically. How high					129)
	above the table is the center of mass (or center of gravity) of the rope when half of the rope has
	lifted off the table?
	A) 0.75 m	B) 1.0 m	C) 1.5 m	D) 0.50 m	E) 0.25 m
130)	Three masses are located in the x–y plane as follows: a mass of 6 kg is at (0 m, 0 m), a mass of 4 kg					130)
	is at (3 m, 0 m), and a mass of 2 kg is at (0 m, 3 m). Where is the center of mass (or center of
	gravity) of the system?

1. (1 m, 2 m)
2. (1 m, 1 m)
3. (0.5 m, 1 m)
4. (1 m, 0.5 m)
5. (2 m, 1 m)

 

 

 

 

 

 

21

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

131) Three balls are moving along a straight line having the instantaneous positions shown in

131)

the figure. At that instant, find the location and velocity of the center of mass (or center of gravity) of this system.

 

 

 

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

132)	A 30-kg child stands at one end of a floating 20-kg canoe that is 5.0-m long and initially at rest in					132)
	the water. The child then slowly walks to the other end of the canoe. How far does the canoe move
	in the water, assuming water friction is negligible?
	A) 3.0 m	B) 1.0 m	C) 5.0 m	D) 4.0 m	E) 2.0 m
133)	The center of mass (or center of gravity) of a two-particle system is at the origin. One particle is					133)
	located at (3.0 m, 0.0 m) and has a mass of 2.0 kg. The other particle has a mass of 3.0 kg. What is
	the location of the 3.0-kg particle?
	A) (3.0 m, 0.0 m)	B) (-3.0 m, 0.0 m)		C) (-2.0 m, 0.0 m)	D) (2.0 m, 0.0 m)

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

134) Three small masses are positioned at the following coordinates: 3.0 kg at (3.0 m, 2.0 m); 4.0 134) kg at (0.0 m, -1.0 m); and 5.0 kg at (5.0 m, -7.0 m). What are the coordinates of the center

 

of mass (or center of gravity) of this system?

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

135)	Three small masses are positioned as follows: 2.0 kg at (0.0 m, 0.0 m), 2.0 kg at (2.0 m, 0.0 m), and				135)
	4.0 kg at (2.0 m, 1.0 m). Determine the coordinates of the center of mass (or center of gravity) of
	this system.
	A) (1.5 m, 0.50 m)	B) (0.50 m, 1.5 m)	C) (2.5 m, 1.5 m)	D) (2.5 m, 0.50 m)
136)	Three masses, 1.0 kg, 2.0 kg, and 3.0 kg, are located at (0.0 m, 0.0 m), (1.0 m, 1.0 m), and (2.0 m,				136)
	-2.0 m), respectively. What is the location of the center of mass (or center of gravity) of this system?
	A) (1.3 m, 0.67 m)		B) (1.3 m, -0.67 m)
	C) (-1.3 m, -0.67 m)		D) (-1.3 m, 0.67 m)
137)	A 3.0-kg mass is located at (0.0 m, 8.0 m), and a 1.0-kg mass is located at (12 m, 0.0 m). You want				137)
	to add a 4.0-kg mass so that the center of mass (or center of gravity) of the three-mass system will
	be at the origin. What should be the coordinates of the 4.0-kg mass?
	A) (-6.0 m, -3.0 m)		B) (-12 m, -8.0 m)
	C) (-3.0 m, -6.0 m)		D) (3.0 m, 6.0 m)

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

138) A 1.0-g bead is at (-2.0 cm, 2.0 cm), a 2.0-g bead is at (2.0 cm, -4.0 cm), and a 3.0-g bead

138)

is at (2.0 cm, 0.0 cm). What are the coordinates of the center of mass (or center of gravity)

of this system of beads?

 

 

 

 

 

22

 

139) Consider the sun and its largest planet Jupiter. On the line joining them, how far from the

139)

center of the sun is their center mass? Is it within or outside the sun? (Jupiter-sun distance is 778 × 10⁶ km, diameter of the sun is 1.4 × 10⁶ km, the sun is 1000 times as massive as Jupiter)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

23

 

Answer Key

Testname: UNTITLED7

 

 

• B
• B, E
• D
• C
• A
• B
• B
• A
• C
• A
• B
• C, D
• A
• B
• C
• A
• A
• E
• B
• B, C
• A
• C
• E
• B
• D
• E
• B, C
• A
• B
• D
• B
• A
• E
• E
• A
• B
• 30 kg · m/s

 

• B
• C
• D
• B
• E
• C
• A
• 123 kg . m/s , 212°
• D
• A
• 60 m/s
• 875 m/s
• 280 m/s

 

 

24

 

Answer Key

Testname: UNTITLED7

 

 

• D
• D
• 7 m/s
• D
• A
• C
• B
• B
• E
• D
• A
• B
• A
• B
• 8 N · s
• 4900 N

67) (a) 0.20 kN     (b) 100

• 17 N s
• D
• C
• D
• D
• D
• 64 ms
• C
• D
• D
• C
• E
• C
• B
• B
• A
• 6 ×10²⁵ per second

 

• B
• 57 m/s
• A
• A
• D
• A
• D
• A
• C
• A
• B
• E
• B
• A

99)	(a) 1.2 m/s toward the east   (b) 4.9 m/s toward the east   (c) Yes, it is an elastic collision.
100)	6.3 m/s

 

25

 

Answer Key

Testname: UNTITLED7

 

 

• 3 m/s
• E
• B
• C
• B
• E
• E
• A
• B
• C
• E

112) (a) 18 N · s     (b) 31%

• B
• D
• A
• E
• E

118) (a) 1.3 m/s     (b) 0.089 m     (c) No, this is an inelastic collision.

• C
• C
• C
• A
• (a) 3.50 cm, (b) 6.13 J during the inelastic collision
• 21 m/s
• A
• B
• B
• C
• E
• D
• 00 m to the right of the 2.00 kg ball, 1.11 m/s to the right
• A
• C
• (2.8 m, -8 m)
• A
• B
• C
• 3 cm, -1.0 cm

 

• 78 × 10⁶ km from the center of the sun, just outside the solar surface