Question 1

Identical forces are exerted for the same length of time on two different objects.The magnitude of the change in momentum of the lighter object is

Accepted Answer

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

Question 2

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?

Accepted Answer

The answer of A 14,000-kg boxcar is coasting at 1.50...

Question 3

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?

Accepted Answer

The answer of A 2200-kg auto moving northward at 12.0...

Question 4

A batter exerts an average force of 8000 N to a baseball for 1.1 ms.What is the magnitude of the impulse exerted on the baseball by the bat?

Accepted Answer

The answer of A batter exerts an average force of...

Question 5

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.)

Accepted Answer

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

Question 6

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?

Accepted Answer

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

Question 7

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

Accepted Answer

A) 361 kg ∙ m/s at 56.3° from the +x-axis 
B) 93.5 kg ∙ m/s at 28.8° from the +x-axis 
C) 21.2 kg ∙ m/s at 39.5° from the +x-axis 
D) 361 kg ∙ m/s at 0.983° from the +x-axis 
E) 21.2 kg ∙ m/s at 56.3° from the +x-axis

Question 8

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?

Accepted Answer

A) 19.1 × 1 $0 ^ { 3 }$ kg∙m/s 
B) 10.2 × 1 $0 ^ { 3 }$ kg∙m/s 
C) 9.55 × 1 $0 ^ { 3 }$ kg∙m/s 
D) 12.0 × 1 $0 ^ { 3 }$ kg∙m/s 
E) 22.2 × 1 $0 ^ { 3 }$ kg∙m/s

Question 9

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 fast was the boy moving just before the collision?

Accepted Answer

The answer of An 80-kg man is skating northward and...

Question 10

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?

Accepted Answer

A) There is a greater average force exerted on the truck. 
B) There is a greater average force exerted on the small car. 
C) There is the same magnitude average force exerted on both the small car and the truck. 
D) The force exerted on each object is inversely proportional to its mass. 
E) The force exerted on each object is directly proportional to its mass.

Question 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

Accepted Answer

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

Question 12

Which of the following quantities are units of momentum? (There could be more than one correct choice.)

Accepted Answer

A) N ∙ m 
B) kg ∙ s/m 
C) kg ∙ m/s 
D) N ∙ s 
E) kg ∙ m2/s2

Question 13

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

Accepted Answer

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

Question 14

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

Accepted Answer

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

Question 15

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?

Accepted Answer

A) 7.21 m/s 
B) 12.2 m/s 
C) 20.4 m/s 
D) 25.0 m/s 
E) 17.3 m/s

Question 16

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?

Accepted Answer

A) 36.9° N of E 
B) 42.0° N of E 
C) 45.0° N of E 
D) 53.1° N of E 
E) 48.0° N of E

Question 17

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?

Accepted Answer

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

Question 18

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 by the bat on the ball?

Accepted Answer

The answer of A 0.17-kg baseball is thrown with a...

Question 19

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?

Accepted Answer

A) 8.3 m/s 
B) 14 m/s 
C) 17 m/s 
D) 22 m/s

Question 20

A 328-kg car moving at 19.1 m/s in the +x direction hits from behind a second car moving at $13.0 \mathrm {~m} / \mathrm { s }$ in the same direction.If the second car has a mass of $790 \mathrm {~kg}$ and a speed of $15.1 \mathrm {~m} / \mathrm { s }$ right after the collision,what is the velocity of the first car after this sudden collision?

Accepted Answer

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

Exam 6: Impulse and Linear Momentum