A
1) 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 momen
C, D
2) Which of the following quantities are units of momentum? (There could be more than one correct choice.)
A) N ? m
B) kg ? s/m
C) kg ? m/s
D) N ? s
E) kg ? m2/s2
C
3) 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)
B) 2
C) 4
D) 8
E) 16
B
4) 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? (T
C
5) The momentum of an isolated system is conserved
A) only in inelastic collisions.
B) only in elastic collisions.
C) in both elastic and inelastic collisions.
B
6) 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
B
7) 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 originall
C
8) 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
E
9) 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 m
C
10) 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 y
B
11) 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) 25 times as great as the momentum change of the heavier fragment.
B) The same as the momentum change of the h
C, D
12) Which of the following quantities are units of impulse? (There could be more than one correct choice.)
A) N ? m
B) kg ? s/m
C) kg ? m/s
D) N ? s
E) kg ? m2/s2
A
13) 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 mo
C
14) 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 exert a larger force on the shells
B) to reduce fric
C
15) In a collision between two unequal masses, which mass receives a greater magnitude impulse?
A) the larger mass
B) the smaller mass
C) They receive equal impulses.
C
16) 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) smaller than the magnitude of the change in momentum of the larger mass, but not zero.
B) larger than the ma
A
17) 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 magni
C
18) 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 truck experiences the greater average force.
B) The small car experie
A
19) In an inelastic collision involving an isolated system, the final total momentum is
A) exactly the same as the initial momentum.
B) more than the initial momentum.
C) less than the initial momentum.
A, D
20) 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 velocity the 5-kg ball experiences
B
21) 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) somewhat inelastic.
B) elastic.
C) comple
A
22) 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) perfectly elastic.
B) partially inelastic.
C) completely inelastic.
D) characterized by an increase
E
23) 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) perfectly elastic.
B) partially inelastic.
C) completely inelastic.
D) ch
C
24) 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) perfectly elastic.
B) partially inelastic.
C) completely inelastic.
D) characterized by an increase
C
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 northward at 2.0 m/s. What is the magnitude of the momentum of this system just after the collision?
A) 14 kg ? m/s
B) 2.0 kg ? m/s
C) 10 kg ? m/s
D) 6.
D
26) 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 kinetic energy is conserved.
B) only its momentum is conserved.
C) both its kinetic energy and its momentum are conserved.
D) only its mechanical e
A, D
27) 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) momentum
B) kinetic energy
C) work
D) impulse
E) force
B
28) 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 the same as before.
B) is half as much as before.
C) is one third as much as before.
D) is one
A
29) 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 cor
C
30) 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 t
A
31) Two objects of different mass have equal, non-zero kinetic energies. Which object has the greater magnitude momentum?
A) the heavier object
B) the lighter object
C) They both have the same magnitude momentum.
B
32) Two objects of different masses have momentum of equal, non-zero magnitude. Which object has more kinetic energy?
A) the heavier object
B) the lighter object
C) They both have the same kinetic energy.
A
33) If you want to double the kinetic energy of a gas molecule, by what factor must you increase its momentum?
A)
B) 2
C) 2
D) 4
E) 16
D
34) If you want to double the momentum of a gas molecule, by what factor must you increase its kinetic energy?
A)
B) 2
C) 2
D) 4
E) 16
A
35) 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
B
36) There must be equal amounts of mass on both sides of the center of mass (or center of gravity) of a system.
A) True
B) False
6.30 kg ? m/s
1) What is the magnitude of the momentum of a 0.140 kg baseball traveling at 45.0 m/s?
B
2) 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 kg ? m/s
B) 0.88 kg ? m/s
C) 0.44 kg ? m/s
D) 0.62 kg ? m/s
E) 1
D
3) 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) +106 kg ? m/s
B) -106 kg ? m/s
C) +14.0 kg ? m/s
D) -14.0 kg ? m/s
E) 0.00 kg ? m/s
B
4) A 0.330-kg volleyball is thrown vertically downward with a speed of 0.150 m/s in a place where g = 9.81 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?
A) 0.212 kg ? m/s
B) 0.262 kg
A
5) 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 o
D
6) 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) 1.8 kg ? m/s
D) 1.5 kg ? m/s
E) 2.4 kg ? m/s
C
7) 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) 0.0280 kg ? m/s upwards
B) 0.028
C
8) 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 momentu
123 kg . m/s , 212�
9) 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.
A
10) 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. What is the magnitude of the change in the car's momentum during the turn?
A) 19.1 � 1 kg?m/s
B) 10.2 � 1 kg?m/s
C) 9.55 � 1 kg?m/s
D) 12.0 � 1 kg?
C
11) 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) 1.2 kg ? m/s
B) 1.8 kg ? m/s
C) 4.4 kg ? m/s
D) 5.4 kg ? m/s
E) 72 kg ? m/s
0.60 m/s
12) 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?
0.875 m/s
13) 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?
0.280 m/s
14) 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?
A
15) A 328-kg car moving at 19.1 m/s in the +x direction hits from behind a second car moving at in the same direction. If the second car has a mass of and a speed of right after the collision, what is the velocity of the first car after this sudden collis
A
16) A 1200-kg ore cart is rolling at 10.8 m/s across a flat friction-free surface. A crane suddenly drops of ore vertically into the cart. How fast does the cart move just after being loaded with the ore?
A) 6.30 m/s
B) 3.80 m/s
C) 4.20 m/s
D) 5.70 m/s
8.7 m/s
17) An empty train car of mass 2.0 x 104 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.
B
18) 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) 0.28 m/s
C) 0.3
A
19) A 1200-kg cannon suddenly fires a cannonball at What is the recoil speed of the cannon? Assume that frictional forces are negligible and the cannon is fired horizontally.
A) 2.9 m/s
B) 35 m/s
C) 3.5 m/s
D) 3.2 m/s
D
20) 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
B
21) 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-a
A
22) 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
E
23) 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) 9.0 m
B) 16 m
C) 21 m
D) 24 m
E)
B
24) 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) 16 m
B) 9.0 m
C) 2
C
25) 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 combin
A
26) 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 in If the mass of the bottle is 500 times the mass of the cork, find the dist
D
27) 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) -100 kg ? m/s
B) -25 kg ? m/s
C) 75 kg ? m/s
D) -75 kg ? m/
E
28) 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
8.8 N ? s
29) 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?
4900 N
30) 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 averag
(a) 0.20 kN (b) 100
31) 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 fo
17 N ? s
32) 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?
D
33) A super dart of mass 20 g, traveling at 350 m/s, strikes a steel plate at an angle of 30� 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 t
C
34) 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) 30 m/s
B) 35 m/s
C
A
35) A 0.140-kg baseball is thrown with a velocity of 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) 1.79
A
36) Calculate the impulse due to a force of that lasts for
A) 6.3 kg? m/s
B) 5.0 kg? m/s
C) 5.7 kg? m/s
D) 6.9 kg? m/s
A
37) 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 and it bounces back with this same speed. The ball is in contact with the wall What is the magnitude of the average force exerted
7.64 ms
38) 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 ba
D
39) 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 f
A
40) 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 what is the average force exerted on the ball by the club?
A) 6.3 kN
B) 7.1 kN
C) 5.5 kN
D) 4.9 kN
A
41) A 0.24 kg blob of clay is thrown at a wall with an initial horizontal velocity of If the clay comes to a stop in what is the average horizontal force on the clay due to the wall?
A) 42 N
B) 26 N
C) 35 N
D) 51 N
C
42) A steady horizontal force lasting for 2.1 s gives a 1.25 kg object an acceleration of 3.2 m/s2 on a frictionless table. What impulse does this force give to the object?
A) 26 kg ? m/s
B) 11 kg ? m/s
C) 8.4 kg ? m/s
D) 2.6 kg ? m/s
A
43) A block of mass m = 34 kg and speed V is behind a block of mass M = 81 kg and speed of 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 What is the magnitude
A
44) 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
C
45) A 0.140-kg baseball is dropped from rest. It has a speed of 1.20 m/s just before it hits the ground, 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
E
46) A batter hits a foul ball. The 0.14-kg baseball that was approaching him at 40 m/s leaves the bat at 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)
A
47) A block of mass m = 5.6 kg, moving on a frictionless surface with a velocity of to the 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 to the left. If the blocks
5.6 �1025 per second
48) A force of 5.3 N is needed to hold on to an umbrella in a strong wind. If the air molecules 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
C
49) A fire hose is turned on the door of a burning building in order to knock the door down. This 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, assumin
7.57 m/s
50) A 2200-kg auto moving northward at 12.0 m/s runs into a 3800-kg truck which is also moving northward, but at 5.00 m/s. If the vehicles lock bumpers, how fast are they moving just after the collision?
A
51) A 1200-kg car moving at suddenly collides with a stationary car of mass If the two vehicles lock together, what is their combined velocity immediately after the collision?
A) 6.9 m/s
B) 8.6 m/s
C) 12.1 m/s
D) 5.5 m/s
E
52) A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s. It suddenly collides directly 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
D
53) A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s. It suddenly collides directly 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 col
C
54) 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 collision is perfectly inelastic, what is the speed of the masses just after the collision?
A) 10 m/s
B) 2.5 m/s
C) 2.0 m/s
D) 0 m/s, since the collision is i
A
55) A block of mass m = 4.4 kg, moving on frictionless surface with a speed makes a 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 bloc
A
56) A block of mass m = 3.6 kg, moving on a frictionless surface with a speed makes a 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 What is
C
57) A 320-g air track cart traveling at 1.25 m/s suddenly collides elastically with a stationary 270-g cart. What is the speed of the 270-g cart just after the collision?
A) 0.678 m/s
B) 0.106 m/s
C) 1.36 m/s
D) 1.14 m/s
E) 2.72 m/s
B
58) A 320-g air track cart traveling at 1.25 m/s suddenly collides elastically with a stationary 270-g cart. What is the speed of the 320-g cart just after the collision?
A) 0.68 m/s
B) 0.11 m/s
C) 0.21 m/s
D) 1.4 m/s
E) 1.1 m/s
D
59) A 550-g ball traveling at 8.0 m/s undergoes a sudden head-on elastic collision with a 250-g ball traveling toward it also at 8.0 m/s. What is the speed of the 250-g mass just after the collision?
A) 15 m/s
B) 8.0 m/s
C) 4.0 m/s
D) 14 m/s
E) 0 m/s
B
60) A 340-g air track cart traveling at 1.25 m/s suddenly collides elastically with a stationary 300-g cart. What is the speed of the 300-g cart just after the collision?
A) 0.0781 m/s
B) 1.33 m/s
C) 0.625 m/s
D) 1.25 m/s
E) 0.664 m/s
C
61) A proton of mass m is at rest when it is suddenly struck head-on by an alpha particle (which 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? (
A
62) A 50-g ball moving at 10 m/s in the +x direction suddenly collides head-on with a stationary ball 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) +3.3 m/
(a) 1.2 m/s toward the east (b) 4.9 m/s toward the east (c) Yes, it is an elastic collision.
63) In a perfectly elastic collision, a 400-g ball moving toward the east at 3.7 m/s suddenly 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 seco
6.3 m/s
64) An 80-kg man is skating northward and happens to suddenly collide with a 20-kg boy 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 fas
14.3 m/s
65) A car (of mass 1500 kg) and a small truck (of mass 2000 kg) collide suddenly at right 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
C
66) Two vehicles approach a right angle intersection and then suddenly collide. After the collision, 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
A
67) A car heading north suddenly collides at an intersection with a truck of the same mass heading east. If they lock together and travel at at 15� north of east just after the collision, how fast was the car initially traveling?
A) 14 m/s
B) 7 m/s
C) 28
C
68) A puck with a mass m1 = 50 g moving at 1.0 m/s approaches a stationary puck with a mass m2 = 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 tra
B
69) A 900-kg car traveling east at 15.0 m/s suddenly collides with a 750-kg car traveling north at 20.0 m/s. The cars stick together after the collision. What is the speed of the wreckage just after the collision?
A) 6.10 m/s
B) 12.2 m/s
C) 25.0 m/s
D) 35
E
70) A 900-kg car traveling east at 15.0 m/s suddenly collides with a 750-kg car traveling north at 20.0 m/s. The cars stick together after the collision. In what direction does the wreckage move just after the collision?
A) 36.9� N of E
B) 42.0� N of E
C)
A
71) A 900-kg car traveling 30.0� south of east at 12.0 m/s suddenly collides with a 750-kg car traveling north at 17.0 m/s. The cars stick together after colliding. What is the speed of the wreckage just after the collision?
A) 7.21 m/s
B) 12.2 m/s
C) 20.
B
72) A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000-kg car traveling 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) 8.3 m/s
B) 14 m/s
C) 17 m
C
73) A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000-kg car traveling 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) 36.9� S of
B
74) Two dogs, Rover and Fido, run on a level frictionless surface. Rover runs eastward with a 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 comb
C
75) A 0.140-kg baseball is dropped from rest from a height of 2.20 m above the ground and 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?
A) 0.
(a) 18 N ? s (b) 31%
76) A 0.32-kg ball is moving horizontally at 30 m/s just before suddenly bouncing off a wall 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 t
B
77) In a police ballistics test, a 2.00-g bullet suddenly hits and becomes embedded in a 5.00-kg wood 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
A
78) A block of mass m = 9.0 kg and speed V and is behind a block of mass M = 27 kg and speed of 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
D
79) As shown in the figure, a bullet of mass 0.010 kg moving horizontally suddenly strikes a block of 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 len
A
80) An 8.0-g bullet is suddenly shot into a 4.0-kg block that is at rest on a frictionless horizontal 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 con
A
81) An 8.0-g bullet is suddenly shot into a 4.0-kg block, at rest on a frictionless horizontal surface, as 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 (
(a) 1.3 m/s (b) 0.089 m (c) No, this is an inelastic collision.
82) In a police rifle test, a 15-g bullet traveling 213 m/s in a vertical direction suddenly buries 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 o
E
83) In a certain nuclear reactor, neutrons suddenly collide with deuterons, which have twice the mass 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 de
C
84) In a certain nuclear reactor, neutrons suddenly collide with carbon nuclei, which have 12 times the 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 c
A
85) An object initially at rest suddenly explodes in two fragments of masses and that move in opposite directions. If the speed of the first fragment is find the internal energy of the explosion.
A) 30 J
B) 30 kJ
C) 38 J
D) 38 kJ
A
86) Two simple pendulums of equal length l = 0.45 m are suspended from the same point. The 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
(a) 3.50 cm, (b) 6.13 J during the inelastic collision
87) On a frictionless horizontal surface, a 1.50-kg mass traveling at 3.50 m/s suddenly collides 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 cons
21 m/s
88) A baseball pitcher is employing a ballistic pendulum to determine the speed of his fastball. A 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
D
89) A 1200-kg pick-up truck traveling south at 15 m/s suddenly collides with a 750-kg car that is traveling east. The two vehicles stick together and slide along the road after colliding. A highway patrol officer investigating the accident determines that
E
90) In the figure, four point masses are placed as shown. Assume that all the numbers in the figure are accurate to two significant figures. What are the x and y coordinates of the center of mass (or center of gravity) of this arrangement?
A) (2.2 m, 2.6
D
91) As shown in the figure, a 60-cm length of uniform wire, of mass 60 g, is bent into a right triangle. What are the x and y coordinates of the center of mass (or center of gravity) of this triangle?
A) (8.0 cm, 3.0 cm)
B) (8.0 cm, 5.0 cm)
C) (9.0 cm, 4.
A
92) 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 is the center of mass (or center of gravity) of the man-board system?
A) 1.25 m
B) 2.50 m
C) 5.00 m
D) 7.50 m
E) 9.00 m
A
93) A 2.0-m rope is lying on a table. You pick up one end and start raising it vertically. How high 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) 0.25 m
B) 0.50 m
C) 0.75 m
D) 1
D
94) 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 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?
A) (1 m, 2 m)
B) (2 m, 1 m)
7.00 m to the right of the 2.00 kg ball, 1.11 m/s to the right
95) Three balls are moving along a straight line having the instantaneous positions shown in the figure. At that instant, find the location and velocity of the center of mass (or center of gravity) of this system.
C
96) 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 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
B
97) The center of mass (or center of gravity) of a two-particle system is at the origin. One particle is 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,
(2.8 m, -2.8 m)
98) Three small masses are positioned at the following coordinates: 3.0 kg at (3.0 m, 2.0 m); 4.0 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?
B
99) 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 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) (0.50 m, 1.5 m)
B) (1.5 m, 0.50 m
B
100) 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, -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) (-
A
101) 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 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
1.3 cm, -1.0 cm
102) 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 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?
0.78 � 106 km from the center of the sun, just outside the solar surface
103) Consider the sun and its largest planet Jupiter. On the line joining them, how far from the 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 i