Momentum and Momentum and CollisionCollision

Practice Problems and Practice Problems and AnswersAnswers

PROBLEM 1PROBLEM 1

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A 2250 kg pickup truck has a velocity A 2250 kg pickup truck has a velocity of 25 m/s to the east. What is the of 25 m/s to the east. What is the momentum of the truck?momentum of the truck?

PROBLEM 2PROBLEM 2

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What velocity must a car with a mass What velocity must a car with a mass of 1210 kg have in order to have the of 1210 kg have in order to have the same momentum as the pickup truck?same momentum as the pickup truck?

A baseball of mass 0.14 kg is moving at 35 m/s. A) Find the momentum of the baseball.

B) Find the velocity of a bowling ball, mass 7.26 kg, would have if its momentum is the same as the baseball.

PROBLEM 3PROBLEM 3

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A compact car, mass 725 kg, is moving at 60 m/s. A) Find its momentum. B) At what velocity is the momentum of a larger car, mass 2175 kg, equal to that of the smaller car?

PROBLEM 4PROBLEM 4

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A snowmobile has a mass of 250 kg. A constant force is exerted on it for 60 s. The snowmobile’s initial velocity is 6 m/s and its final velocity is 28 m/s. A) what is the change in momentum? B) what is the magnitude of the force exerted?

PROBLEM 5PROBLEM 5

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The brakes exerted a 640 N force on a car weighing 15689 N and moving at 20 m/s. The car finally stops. A) What is the car’s mass? B) What is the car’s initial momentum? C) What is the change in the car’s momentum?D) How long does the braking force act on the car to bring it to a halt?

PROBLEM 6PROBLEM 6

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What impulse is needed to stop a 45 g mass traveling at 42 m/s?

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PROBLEM 7PROBLEM 7

Which has the greater momentum: a 145 g baseball traveling at 40 m/s or 45 g golf ball traveling at 67 m/s?

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PROBLEM 8PROBLEM 8

A force of 540 N is used to stop anobject with a mass of 65 kg moving at175 m/s. How long will it take to bringthe object to a full stop?

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PROBLEM 9PROBLEM 9

In hitting a stationary hockey puckhaving a mass of 180g, a hockeyplayer gives the puck an impulse of6 N*s. At what speed will the puck movetoward the goal?

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PROBLEM 10PROBLEM 10

Before Before Collision Collision

After After Collision Collision

Person Person 0 0 60 * v 60 * v

Medicine ball Medicine ball 300 300 15 * v 15 * v

Total Total 300 300 300 300

km/hr 4 v

300 75v

300 15v 60v

Before Collision Before Collision After Collision After Collision

Granny Granny 80 * 6 = 480 80 * 6 = 480 80 * v 80 * v

Ambrose Ambrose 0 0 40 * v 40 * v

Total Total 480 480 480 480

4m/s v

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480 40v 80v

Before Collision Before Collision After Collision After Collision

Truck Truck 3000 * 10 = 30 000 3000 * 10 = 30 000 3000 * v 3000 * v

Car Car 0 0 1000 * 15 = 15 000 1000 * 15 = 15 000

Total Total 30 000 30 000 30 000 30 000

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Glider A of mass .355 kg moves along a frictionless air track with a velocity of .095 m/s. It collides with a glider B of mass .710 kg moving in the same direction at a speed of .045 m/s. After collision glider A continues in the same direction with a velocity of .035 m/s. What is the velocity of glider B after collision?

PROBLEM 11PROBLEM 11

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A .105 kg hockey puck moving at 48m/s is caught by a 75kg goalie at rest. With what speed does the goalie slide on the ice?

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PROBLEM 12PROBLEM 12

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A 35 g bullet strikes a 5 kg stationary wooden block and embeds itself in the block. The block and the bullet fly off together at 8.6m/s. What is the original velocity of the bullet?

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PROBLEM 13PROBLEM 13

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A 35 g bullet moving at 475m/s strikes a 2.5 kg wooden block. The bullet passes through the block, leaving at 275 m/s. The block was at rest when it was hit. How fast is it moving when the bullet leaves ?

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PROBLEM 14PROBLEM 14

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An astronaut at rest in space with mass 84kg fires a thruster that expels 35g of hot gas at 875m/s. What is the velocity of the astronaut after the firing shot?

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PROBLEM 15PROBLEM 15

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A 4 kg model rocket is launched, shooting 50g fuel from its exhaust at an average velocity of 625 m/s. What is the velocity of the rocket after the fuel has burned? (Ignore effects of gravity and air resistance)

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PROBLEM 16PROBLEM 16

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Two campers dock a canoe. One camper steps on the dock. This camper has a mass of 80 kg and moves forward at 4 m/s. With what speed and direction do the canoe and the other camper move if their combined mass is 110 kg?

PROBLEM 17PROBLEM 17

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Two students on roller skates stand face to face, then push each other away. One student has a mass of 90 kg, the other 60 kg. Find the ratio of their velocities just after their hands lose contact. Which student has the greater speed?

PROBLEM 18PROBLEM 18

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Block A with a mass 12 kg Block A with a mass 12 kg moving at 2.4 m/s makes a moving at 2.4 m/s makes a perfect elastic head-on perfect elastic head-on collision with a block B, collision with a block B, mass 36 kg, at rest. Find the mass 36 kg, at rest. Find the velocities of the two blocks velocities of the two blocks after collision. Assume all after collision. Assume all motion is in one dimension.motion is in one dimension.

PROBLEM 19PROBLEM 19

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PROBLEM 20PROBLEM 20

A 2575 kg van runs into the A 2575 kg van runs into the back of a 825kg compact back of a 825kg compact car at rest. They move off car at rest. They move off together at 8.5 m/s. together at 8.5 m/s. Assuming no friction with Assuming no friction with the ground, find the initial the ground, find the initial speed of the van.speed of the van.

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PROBLEM 21PROBLEM 21

A 5g bullet is fired with a A 5g bullet is fired with a velocity of 100 m/s toward a velocity of 100 m/s toward a 10 kg stationary solid lock 10 kg stationary solid lock resting on a frictionless resting on a frictionless surface. What is the change surface. What is the change in momentum of the bullet if in momentum of the bullet if it becomes embedded in the it becomes embedded in the block?block?

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PROBLEM 22PROBLEM 22

A 50 g ball is struck with a club. The A 50 g ball is struck with a club. The force on the ball varies from zero force on the ball varies from zero when contact is made up to some when contact is made up to some maximum value (when the ball is maximum value (when the ball is deformed) and then back to zero deformed) and then back to zero when the ball leaves the club. when the ball leaves the club. Assume the ball leaves the club face Assume the ball leaves the club face with a velocity of +44 m/s. Estimate with a velocity of +44 m/s. Estimate the impulse due to the collision.the impulse due to the collision.

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PROBLEM 23PROBLEM 23

In a particular car test, a 1.50 x 10In a particular car test, a 1.50 x 1033 kg kg automobile collides with a wall. automobile collides with a wall. The initial and final velocities of the The initial and final velocities of the automobile are –15 m/s and 2.6 automobile are –15 m/s and 2.6 m/s respectively. If the collision m/s respectively. If the collision lasts for 0.150s, find the impulse lasts for 0.150s, find the impulse due to collision and the average due to collision and the average force exerted on the automobile.force exerted on the automobile.

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PROBLEM 24PROBLEM 24

A baseball player attempts to use a A baseball player attempts to use a pitching machine to help him improve pitching machine to help him improve his batting average. He places the 50 kg his batting average. He places the 50 kg machine on a frozen pond. The machine machine on a frozen pond. The machine fires a 0.15 kg baseball horizontally with fires a 0.15 kg baseball horizontally with a speed of 36 m/s. What is the recoil a speed of 36 m/s. What is the recoil velocity of the machine?velocity of the machine?

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PROBLEM 25PROBLEM 25

An 1800 kg luxury sedan stopped at a An 1800 kg luxury sedan stopped at a traffic light is struck from the rear by traffic light is struck from the rear by a compact car with a mass of 900 kg. a compact car with a mass of 900 kg. The two cars became entangled as a The two cars became entangled as a result of the collision. If the compact result of the collision. If the compact car was moving at a velocity of +20 car was moving at a velocity of +20 m/s before the collision, what is m/s before the collision, what is velocity of the entangled mass after velocity of the entangled mass after the collision?the collision?

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