Deck 7: Momentum and Collisions

Question 1

In an elastic collision,

A)momentum is not conserved.
B)kinetic energy is not conserved.
C)kinetic energy is conserved.
D)None are correct.

Answer 1

kinetic energy is conserved.

Question 2

An empty railroad car traveling at a speed of 21 m/s strikes a second car at rest.The second car,being full with passengers,has twice the mass of the first car.If the cars lock together as a result of the collision,their common speed afterward is

A)11 m/s.
B)10 m/s.
C)9.0 m/s.
D)8.0 m/s.
E)7.0 m/s.

Answer 2

7.0 m/s.

Question 3

The sum of the forces acting on an object is equal to

A)the object's momentum.
B)the impulse the object receives.
C)the rate of change of the object's momentum.
D)None are correct.

Answer 3

the rate of change of the object's momentum.

Question 4

Astronauts are playing baseball on the International Space Station.One astronaut with a mass of 60.0 kg,initially at rest,hits a baseball with a bat.The baseball was initially coming toward the astronaut at 30.0 m/s and after the ball is hit,the ball travels in the opposite direction with a speed of 50.0 m/s.The mass of a baseball is 0.120 kg.The recoil velocity of the astronaut is

A)0.224 m/s.
B)0.160 m/s.
C)0.356 m/s.
D)0.478 m/s.
E)0.552 m/s.

Question 5

Particle one of mass m initially moves to the right at v.Particle two of mass 2m is initially at rest.After they undergo an elastic collision,particle one moves directly down.What is the final speed of particle two?

A)0.577 v
B)0.707 v
C)0.500 v
D)0.250 v
E)0.764 v

Question 6

An object initially at rest explodes into three pieces,each of which has the same mass.Piece one moves north and piece two moves east.Which piece has the largest speed?

A)piece one
B)piece two
C)piece three
D)They all have the same speed.

Question 7

Particle one of mass m initially moves to the right at v.Particle two of mass 3m is initially at rest.After they undergo an elastic collision,particle one moves directly down.In what direction does particle two move relative to the initial direction of particle one?

A)63^o
B)60^o
C)35^o
D)30^o
E)26^o

Question 8

A 0.280-kg ball makes an elastic head-on collision with a second ball initially at rest.The second ball moves off with one fourth the original speed of the first ball.What is the velocity of the first ball after the collision,in terms of its initial velocity,v?

A)-0.16v
B)+0.16v
C)-0.25v
D)+0.25v
E)0
F) +0.75v
G) -0.75v

Question 9

An SUV of mass 2200 kg,moving with a speed of 35 m/s on the highway,passes a car with the mass 1500 kg and a kinetic energy equal to that of the SUV.The ratio of the momentum of the car relative to that of the SUV is

A)0.75
B)0.83
C)0.46
D)1.0
E)0.68

Question 10

I run toward the wall at 5.00 m/sec to the left.My mass is 90.0 kg.I collide with the wall and come to rest in 0.100 sec.What was the average normal force on my body due to the wall?

A)4.50 N
B)45.0 N
C)450 N
D)4500 N

Question 11

An SUV of mass 2200 kg,moving with a speed of 35 m/s on the highway,passes a car with the mass 1500 kg and a kinetic energy equal to that of the SUV.The ratio of the momentum of the SUV relative to that of the car is

A)0.68
B)1.21
C)1.0
D)1.47
E)0.83

Question 12

An SUV of mass 2200 kg,moving with a speed of 35 m/s on the highway,passes a car with the mass 1500 kg and a linear momentum equal to that of the SUV.The ratio of the kinetic energy of the SUV relative to that of the car is

A)0.12.
B)0.33.
C)0.68.
D)0.75.
E)1.0.

Question 13

A 1000-kg car is travelling west at 17.0 m/s toward an intersection.A 1500-kg truck is travelling north at 20.0 m/s toward the same intersection.The car and truck collide at the intersection and stick together.What is their speed after the collision?

A)13.8 m/s
B)15.3 m/s
C)18.8 m/s
D)19.0 m/s
E)21.0 m/s

Question 14

A 1000-kg car is travelling west at 17.0 m/s toward an intersection.A 1500-kg truck is travelling north at 20.0 m/s toward the same intersection.The car and truck collide at the intersection and stick together.What is the final kinetic energy of the system?

A)1.36 * 10⁵ J
B)1.72 * 10⁵ J
C)2.38 * 10⁵ J
D)4.76 * 10⁵ J

Question 15

A child in a sled is moving with a speed of 4.0 m/s across an iced over pond.If the total mass of the sled-child system is 85.0 kg,what magnitude of the average force is required to bring the sled to rest in 10.0 s?

A)14 N
B)24 N
C)34 N
D)44 N
E)54 N

Question 16

An SUV of mass 2200 kg,moving with a speed of 35 m/s on the highway,passes a car with the mass 1500 kg and a linear momentum equal to that of the SUV.The ratio of the kinetic energy of the car relative to that of the SUV is

A)0.68
B)1.47
C)1.0
D)0.83
E)1.21

Question 17

A 0.280-kg ball makes an elastic head-on collision with a second ball initially at rest.The second ball moves off with one fourth the original speed of the first ball.The mass of the second ball is

A)1.12 kg.
B)0.280 kg.
C)2.24 kg.
D)1.96 kg.
E)0.560 kg.

Question 18

Consider two carts,of masses m and 2m,at rest on a frictionless air track.You push the first cart for 3 s and then the other for the same length of time and with the same force.The final speed of the cart with mass 2 m is

A)one third the speed of the cart of mass m.
B)one fourth the speed of the cart of mass m.
C)one half the speed of the cart of mass m.
D)the same as the cart of mass m.

Question 19

A 1000-kg car is travelling west at 17.0 m/s toward an intersection.A 1500-kg truck is travelling north at 20.0 m/s toward the same intersection.The car and truck collide at the intersection and sick together.What is the angle of their velocity after the collision relative to the east direction?

A)60.5 degrees
B)75.5 degrees
C)95.5 degrees
D)120 degrees
E)150 degrees

Question 20

Particle one of mass m initially moves to the right at v.Particle two of mass 4m is initially at rest.After they undergo an elastic collision,particle one moves directly down.What is the final speed of particle one?

A)0.316 v
B)0.775 v
C)0.200 v
D)0.800 v
E)0.707 v

Question 21

Consider two carts,of masses m and 2m,at rest on a frictionless air track.If you push the first cart for 3 m and then the other for the same length of distance with the same force,which cart undergoes the smallest change in momentum?

A)the cart with mass m
B)the cart with mass 2m
C)The change in momentum is the same in each case.
D)There is no change in momentum in either cart.
E)Impossible to tell.

Question 22

Consider two carts,of masses m and 2m,at rest on a frictionless air track.If you push the first cart for 3 m and then the other for the same length of distance with the same force,which cart undergoes the largest change in momentum?

A)the cart with mass m
B)the cart with mass 2m
C)The change in momentum is the same in each case.
D)There is no change in momentum in either cart.
E)Impossible to tell.

Question 23

A hockey puck with mass 0.250 kg traveling along a line at 2.5 m/s strikes a stationary puck with the same mass.One puck exits the elastic collision in a direction that is 20 degrees away from the line at a speed of 2.35 m/s.What is the angle with respect to the line in which the second puck travels after the collision?

A)0 ^$\circ$
B)-20 ^$\circ$
C)-60 ^$\circ$
D)-70 ^$\circ$
E)-90 ^$\circ$

Question 24

A 57-kg archer on ice skates launches a 32.4-g arrow traveling 65 m/s.If the archer is initially at rest and can recoil without friction,the speed of the archer after the arrow launch is

A)0.0369 m/s.
B)0.0284 m/s.
C)0.0154 m/s.
D)0.0415 m/s.
E)0.0642 m/s.

Question 25

A bomb explodes into three pieces of mass m,2m,and 3m.The mass m piece flies into the + x direction.The 2m piece flies in the + y direction.If all pieces fly off with the same velocity,what is the angle of the third piece with respect to the + x axis?

A)180.0 degrees
B)243.4 degrees
C)124.3 degrees
D)84.5 degrees
E)More information is needed.

Question 26

A 49.5-g tennis ball traveling at 18.2 m/s is hit by a tennis racket which applies a force of 25.7 N to the ball for 16.3 ms.The impulse that the racket applies to the tennis ball is

A)1.62 Ns.
B)25.7 Ns.
C)1577 Ns.
D)0.4189 Ns.
E)8.46 Ns.

Question 27

A tennis ball (m = 57 g)falls down and hits the ground with a speed of 15 m/s and rebounds upward with a speed of 6 m/s.If the collision with the earth occurs during over a time of 0.31 s,find the maximum force on the ball.

A)0.37N
B)1.7 N
C)3.9 N
D)More information is needed.

Question 28

Consider two carts,of masses m and 2m,at rest on a frictionless air track.If you push the first cart for 3 m and then the other for the same length of distance with the same force,which cart undergoes the smallest change in kinetic energy?

A)the cart with mass m
B)the cart with mass 2m
C)The change in kinetic energy is the same in each case.
D)There is no change in kinetic energy in either cart.
E)Impossible to tell.

Question 29

A tennis ball (m = 57 g)hits a wall at an angle of 25 degrees with respect to the normal line (perpendicular to the wall).The initial speed is 12 m/s and it rebounds with the same speed.Find the magnitude of the impulse delivered by the wall.

A)0.58 kg m/s
B)1.2 kg m/s
C)1.4 kg m/s
D)More information is needed.

Question 30

A 300-g billiard ball travelling at 2 m/s collides elastically with an identical stationary billiard ball and bounces off at a 30 degree angle.What is the angle of the other ball's path with respect to the path of the original ball?

A)15 degrees
B)17 degrees
C)22.5 degrees
D)60 degrees
E)More information is needed.

Question 31

A hockey puck with mass 0.250 kg traveling along a line at 2.5 m/s strikes a stationary puck with the same mass.One puck exits the elastic collision in a direction that is 20 degrees away from the line at a speed of 2.35 m/s.What is the speed of the second puck after the collision?

A)0.85 m/s
B)2.5 m/s
C)0.63 m/s
D)0.73 m/s
E)0.15 m/s

Question 32

Which of the following have the highest ratio of kinetic energy to momentum,K/p?

A)an asteroid with mass 10⁶ kg and speed 500 m/s
B)a high-speed train with a mass of 180,000 kg and a speed of 300 km/hr
C)a 120-kg linebacker with a speed of 10 m/s
D)a 10-kg cannon with a speed of 120 m/s
E)a proton with a mass of 6 * 10^-27 kg and a speed of 2 * 10⁵ m/s

Question 33

A 1900-kg car hits a parked 2200-kg car at 32 m/s and sticks to it.What is the velocity of the two cars after the collision?

A)12.3 m/s
B)32.0 m/s
C)14.8 m/s
D)0.0 m/s
E)16.2 m/s

Question 34

Which of the following have the highest ratio of momentum to kinetic energy,p/K?

A)an asteroid with mass 10⁶ kg and speed 500 m/s
B)a high-speed train with a mass of 180,000 kg and a speed of 300 km/hr
C)a 120-kg linebacker with a speed of 10 m/s
D)a 10-kg cannon with a speed of 120 m/s
E)a proton with a mass of 6 * 10^-27 kg and a speed of 2 *10⁵ m/s

Question 35

An explosion inside a mortar tube launches a 100-kg projectile directly upward with a speed of 350 m/s.The increase in the Earth's kinetic energy due to this explosion is (mass of the Earth is

A)3.50 * 10⁴ J.
B)1.02 * 10^-16 J.
C)1.22 * 10⁷ J.
D)6.35 * 10^-7 J.
E)8.92 * 10² J.

Question 36

A railroad water tanker car with a total mass of 1.50·10⁵ kg rolls without friction or air resistance along a straight,level track at a constant speed of 5.74 m/s.As the car rolls it springs a leak at the bottom of the tank,releasing a stream of water going straight down.What is the speed of the car after the 6.35·10⁴ kg of water have leaked out of the car?

A)4.75 m/s
B)13.6 m/s
C)9.95 m/s
D)12.5 m/s
E)5.74 m/s

Question 37

In the movies a person hit by a bullet goes flying back from the momentum of the bullet (typically into a plate-glass window),find the final speed of a 84-kg man just after he is hit by a 44magnum bullet of mass 16 g traveling at a speed of 470 m/s.

A)0.090 m/s
B)0.25 m/s
C)5.6 m/s
D)7.5 m/s

Question 38

A tennis ball (m = 57 g)falls down and hits the ground with a speed of 15 m/s and rebounds upward with a speed of 6.0m/s.If the collision with the earth occurs during a time interval of 0.31 s,find the average force on the ball.

A)0.37 N
B)1.7 N
C)3.9 N
D)More information is needed.

Question 39

An empty railroad car traveling at a constant speed strikes a second car at rest.The second car,being full with passengers,has twice the mass of the first car.If the cars lock together as a result of the collision,the ratio of the initial to the final kinetic energies of the system is

A)1.
B)1/3.
C)3.
D)1/9.
E)9.

Question 40

A golf-ball (m = 0.045 kg)is at rest on a tee when an average force of 5880 N,directed 12 degrees above the horizon,is applied by a golf-club over a time of 0.45 ms.Find the range of the golf ball.

A)58m
B)60.m
C)120m
D)140m

Question 41

A golf ball bounces to a height of 7.60 m after its second bounce after being dropped onto the sidewalk from a 20.5-m high pedestrian overpass.How high does the golf ball bounce after its first collision with the sidewalk?

A)14.1 m
B)15.6 m
C)13.8 m
D)10.9 m
E)12.5 m

Question 42

A spring is compressed between two blocks,block A of mass m,and block B of mass 3m.The 1250 N/m spring is released,sending the blocks in opposite directions.What is the ratio of kinetic energies of block A to block B,K_A/K_B?

A)1/3
B)3
C)1
D)1/9
E)More information is needed.

Question 43

A 45-kg girl skating due south at 7 m/s collides with a 30-kg boy moving east at 5 m/s.Their common velocity in m/s is

A)3 - 7
.
B)2 - 4.2
.
C)5 - 9
.
D)6 - 3

Question 44

A spring is compressed between two blocks,block A of mass m,and block B of mass 3m.The 1250 N/m spring is released,sending the blocks in opposite directions.What is the ratio of the magnitudes of the momenta of block A to block B,p_A/p_B?

A)1
B)1/3
C)More information is needed.
D)3
E)1/9

Question 45

A rolling steel ball bearing of mass 27.5 g collides elastically with a small toy car of mass 52.0 g.If after the collision,the car moves at 1.25 m/s to the right,with what speed and direction is the ball bearing rolling afterward?

A)1.7 m/s left
B)1.7 m/s right
C)0.56 m/s left
D)0.56 m/s right
E)2.4 m/s left

Question 46

A 60-kg man is standing on a 200-kg cart moving to the right at a speed of 5 m/s on frictionless tracks.If the man starts to walk to the left with a speed of 1 m/s relative to the cart,what is the final speed of the man with respect to the tracks?

A)4.67 m/s
B)5.28 m/s
C)6.49 m/s
D)4.23 m/s

Question 47

Rebecca of mass 50 kg and Robert of mass 60 kg are initially at rest on a frictionless frozen lake.Robert throws a book of mass 0.50 kg at Rebecca with 20 m/s relative to the ice.Rebecca catches the book.Assuming the book is traveling horizontally,their final speeds are

A)V_Reb = 12.0 m/s,V_Rob = 17.0 m/s.
B)V_Reb = 1.51 m/s,V_Rob = 4.17 m/s.
C)V_Reb = 0.20 m/s,V_Rob = 0.17 m/s.
D)V_Reb = 0.12 m/s,V_Rob = 6.17 m/s.

Question 48

Throwing caution to the wind,Bob hops off a bridge onto a small boat that is travelling under the bridge at 12.0 m/s.If Bob's mass is 85.0 kg,and the boat's (with its driver)is 451 kg,how fast is the boat moving after Bob lands on it? Assume Bob falls straight down into the boat.

A)9.7 m/s
B)10.1 m/s
C)11.0 m/s
D)14.3 m/s

Question 49

Rank the time intervals from least to greatest that are required to stop the following objects using the associated constant forces: (1)A 0.140-kg baseball travelling at 43 m/s using a force of 150 N,(2)A 0.185-kg softball travelling at 35 m/s using a force of 190 N,(3)A 0.162-kg cricket ball travelling at 38 m/s using a force of 170 N,and finally (4)a 0.127-kg hockey puck travelling at 47 m/s using a force of 145 N.

A)1,2,3,4
B)4,1,3,2
C)2,3,1,4
D)3,4,2,1

Question 50

A 60-kg man is standing on a 200-kg cart moving to the right at a speed of 5 m/s on frictionless tracks.If the man starts to walk to the left with a speed of 1 m/s relative to the cart,what is the final speed of the cart?

A)3.18 m/s
B)4.67 m/s
C)5.23 m/s
D)6.49 m/s

Question 51

A 120-g ball thrown at 25 m/s is struck by a bat which gives it a velocity of 30 m/s in the opposite direction.If the time of contact is 0.01 s,the magnitude of the average force experienced by the ball is

A)3000 N.
B)1000 N.
C)660 N.
D)60 N.

Question 52

A golf ball bounces to a height of 7.60 m after its second bounce after being dropped onto the sidewalk from a 20.5-m high pedestrian overpass.What is the coefficient of restitution for the golf ball -- sidewalk collision?

A)0.609
B)0.551
C)0.780
D)0.371
E)1

Question 53

A rolling steel ball bearing of mass 27.5 g collides elastically with a small toy car of mass 52.0 g.If after the collision,the car moves at 1.25 m/s to the right,with what direction and speed was the ball bearing rolling prior to the collision?

A)0.56 m/s right
B)1.70 m/s left
C)1.81 m/s right
D)1.81 m/s left
E)2.41 m/s right

Question 54

The forces shown in the force vs.time graph act on a 1.5-kg particle.If the particle is initially at rest,find the particle's speed at t = 5 s?

A)0.67 m/s
B)6.7 m/s
C)0 m/s
D)6 m/s
E)7 m/s

Question 55

A rubber ball and a clay ball have identical shapes and masses.Each is thrown horizontally with the same speeds toward identical wooden blocks.The rubber ball bounces off its block,whereas,the clay ball sticks its block.Which ball is more likely to knock its block off balance?

A)clay ball
B)rubber ball
C)Both balls have the same chance.
D)More information is needed.

Question 56

Two billiard balls undergo a glancing collision.Before the collision the first ball was travelling east at 2.6 m/s and the second ball was travelling west at 1.2 m/s.After the collision the second ball is deflected by +90 degrees travelling north at 1.47 m/s.Working in a coordinate system where +x direction is east and +y direction is north,what is the direction of the first ball after the collision?

A)46.4º south of east
B)43.6º south of east
C)46.4º south of west
D)43.6º south of west

Question 57

A 8-kg object with a velocity 5 m/s explodes into two fragments of equal mass.One flies off with a velocity of (3 -2 )m/s.The velocity of the other fragments is

A)7 + 2
m/s.
B)8 + 3
m/s.
C)47 - 2
m/s.
D)7 - 2

Question 58

Two billiard balls undergo a glancing collision.Before the collision the first ball was travelling east at 2.6 m/s and the second ball was travelling west at 1.2 m/s.If the second ball is deflected by +90 degrees travelling north at 1.47 m/s,what is the speed of the first ball after the collision?

A)1.39 m/s
B)1.68 m/s
C)2.57 m/s
D)2.03 m/s

Question 59

A 35-kg boy runs at 2.5 m/s and leaps onto a tire swing,the mass of which is 28 kg.If the maximum angle the swing reaches is 6.7 degrees,how long is the tire swing?

A)5.8 m
B)7.2 m
C)14 m
D)26 m

Question 60

A golf ball bounces to a height of 7.60 m after its second bounce after being dropped onto the sidewalk from a 20.5-m high pedestrian overpass.With what speed did it impact the sidewalk just before its second bounce?

A)11.0 m/s
B)12.2 m/s
C)13.8 m/s
D)15.6 m/s
E)20.0 m/s

Question 61

A hockey puck with a mass of 160 g slides at a speed of 12 m/s on frictionless ice.The puck runs into a small box with a mass of 850 g that is initially at rest.Assuming that the collision is elastic,what is the speed of the hockey puck after the collision?

A)5.6 m/s
B)8.2 m/s
C)6.0 m/s
D)3.8 m/s
E)2.3 m/s

Question 62

A pendulum with a mass M swings and picks up a piece of clay of mass m at the bottom of its swing.

A)It rises to the same height after the collision as before.
B)The total mechanical energy of the system is unchanged by the collision.
C)If M = m,then the height it reaches after the collision is half that before the collision.
D)If M = m,then the height it reaches after the collision is 1/4 that before the collision.
E)If M = m,then it rises to twice the height it had before the collision.

Question 63

An egg in a special container together have a mass of 148.0 g.The container is designed such that when dropped it will bring the egg to a stop in 0.200 s when it hits the ground.A force of 4.91 N will break the egg.What is the maximum height from which the egg in its container can be dropped and not break the egg? (in m)

A)1.56
B)1.76
C)1.99
D)2.24
E)2.54

Question 64

Ballistic pendulum: A bullet (mass m = 100 g)hits a wood block of mass 9.9 kg,handing from two long cords.The bullet has an initial velocity of 500 m/s.The velocity of the bullet/block combination after this totally inelastic collision is then

A)5 m/s.
B)0 m/s.
C)99 m/s.
D)500 m/s.
E)10 m/s.

Question 65

A cannon fires a 2-kg exploding projectile across a level field on a windless day.The projectile leaves the cannon at a speed of 30 m/s at an angle of 60 degrees with respect to the horizontal.When the projectile reaches its maximum height,it explodes into two 1-kg pieces.One of the pieces falls straight down.How far away from the cannon does the second piece land?

A)34 m
B)40 m
C)79 m
D)92 m
E)120 m

Question 66

An object (m = 0.05 kg)with velocity 20 m/s collides head on with another with mass 0.10 kg at rest.If the first object has a velocity = 0 after the collision,what is the loss in kinetic energy (J)in the collision?

A)10
B)2
C)3
D)4
E)5

Question 67

A 1.50-kg ball makes an elastic head-on collision with a 1.00-kg ball.Before the collision,the speed of the 1.50-kg ball is 1.0 m/s,and the speed of the 1.00-kg ball is zero.The speed of the 1.00-kg ball after the collision is

A)greater than 1.0 m/s,but less than 2.0 m/s.
B)2.0 m/s.
C)less than 1 m/s.
D)1 m/s.
E)zero.

Question 68

A rubber ball is dropped from a height of 8.7 m onto the floor below.It rebounds to a height of 7.2 m.What is the coefficient of restitution for the ball?

A)0.17
B)0.42
C)0.68
D)0.83
E)0.91

Question 69

A hockey puck with a mass of 160 g slides at a speed of 12 m/s on frictionless ice.The puck runs into a small box with a mass of 850 g that is initially at rest.Assuming that the collision is elastic,what is the speed of the box after the collision?

A)2.3 m/s
B)3.8 m/s
C)5.6 m/s
D)6.0 m/s
E)8.2 m/s

Question 70

A golf ball (m = 0.05 kg)and a cannonball (M = 100 kg)collide head-on.Before the collision,the two balls had equal speeds of 30 m/s and opposite directions.After the collision,the speed of the golf ball is approximately

A)0 m/s.
B)15 m/s.
C)30 m/s.
D)60 m/s.
E)90 m/s.

Question 71

In a collision between two objects,what is always conserved?

A)the momentum of each object individually
B)the total momentum of the two objects
C)the kinetic energy of each object individually
D)the total kinetic energy of the two objects
E)More than one of the choices are true.

Question 72

Which of the following statements about collisions is true?

A)Total momentum is conserved in elastic,but not in inelastic collisions.
B)Total kinetic energy is conserved in elastic,but not in inelastic collisions.
C)Total kinetic energy is always conserved.
D)In totally inelastic collisions,all of the kinetic energy is lost.
E)In totally inelastic collisions,all of the momentum is lost.

Question 73

A golf ball of mass 0.0408 kg is dropped from a height h = 1.12 m onto a hard floor and bounces back to exactly that same height.What is the average force on the ball during the 0.012 s that it was in contact with the floor?

A)0 N
B)0.013 N
C)0.408 N
D)8.21 N
E)31.9 N

Question 74

A basketball with a mass of 0.5 kg is bounced on the floor.Right before impact,it has a speed of 10 m/s,and right after it has 8 m/s.What is the impulse of the collision,and of which type is the collision?

A)1 Ns,elastic
B)5 Ns,elastic
C)9 Ns,elastic
D)1 Ns inelastic
E)9 Ns,inelastic

Question 75

A truck moving with a speed of 25.4 m/s strikes a parked car.During the collision the truck and car stick together and slide to a stop together.The moving truck has a total mass of 2434 kg (including driver),and the parked car has a total mass of 1092.0 kg.The coefficient of sliding friction between the tires and the road is 0.520.How far does the truck/car combination slide? (in m)

A)15.43
B)19.29
C)24.11
D)30.13
E)37.67

Question 76

In a totally elastic collision of two billiard balls (2-dimensional elastic collision),which of the following quantities is not conserved?

A)total kinetic energy
B)total momentum
C)x-component of the total momentum
D)total velocity
E)total mass

Question 77

An inelastic collision takes place between two equal masses of 7 kg.One was at rest and the other moving at 17 m/s before and 5 m/s after.How much energy was lost in the collision?

A)420 J
B)0 J
C)67 J
D)4350 J
E)3.4 J

Question 78

In a collision between a small car and a large truck,which of the following pairs of vectors do NOT occur as an equal and opposite pair?

A)the force of the car on the truck compared to the force of the truck on the car
B)the impulse delivered by the car to the truck compared to the impulse delivered by the truck on the car
C)the acceleration of the car compared to the acceleration of the truck
D)the change in momentum of the car compared to the change in momentum of the truck
E)All of the choices occur as an equal and opposite pair.

Question 79

Two cars approach each other and collide head-on.Car 1 has a mass of 800 kg and a velocity of -20 m/s.Car 2 has a mass of 1000 kg and a velocity of +16 m/s.They have an inelastic collision,but don't stick to each other.After the collision,car 1 has a velocity of 5 m/s.What is the fraction of kinetic energy lost?

A)94%
B)89%
C)50%
D)37%
E)18%

Question 80

Two bumper cars on a frictionless surface collide elastically.The first bumper car is moving to the right with a speed of 22.0 m/s and rear-ends a bumper car also moving to the right with a speed of 5.00 m/s.What is the speed of the first bumper car after the collision (in m/s)? The mass of the first bumper car is 192 kg and the mass of the second bumper car is 144 kg.Assume that the collision takes place in one dimension.

A)3.9643
B)4.6382
C)5.4267
D)6.3492
E)7.4286