Physical Science Chapter 3 & 4

A 5000-kg freight car crashes into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000-kg freight car? A. 6 m/s B. 4 m/s C. 8 m/s D. 5 m/s E. none of the above

6 m/s

The greater efficiency achieved with the curved blades of a Pelton wheel is due to A. divided impulse. B. bouncing. C. rotational momentum. D. greater time of water impact.

bouncing

When Peter tosses an egg against a sagging sheet, the egg doesn't break due to A. reduced momentum. B. reduced impulse. C. both of these D. neither of these

neither of these

When a boxer moves into an oncoming punch, the force experienced is A. increased. B. decreased. C. no different, but the timing is different. D. all of the above

increased.

If a charging rhinoceros has momentum, it must also have A. work. B. kinetic energy. C. potential energy. D. all of the above

kinetic energy

Jogging Jake runs along the top of a moving flatcar in the direction of motion of the flatcar. If he runs in the opposite direction, the combined momentum of Jake and the flatcar relative to an observer at rest will be A. the same. B. more. C. less.

less

A melon is projected into the air with 100 J of kinetic energy in the presence of air resistance. When it returns to its initial level its kinetic energy is A. 100 J. B. more than 100 J. C. less than 100 J. D. need more information

less than 100 J

When you can't escape being hit by a fast-moving object, you'll suffer a smaller force if the collision time is A. long. B. short. C. the same way either way

long

Just after a big fish swallows a small fish, the momentum of the two-fish system is A. somewhat less after lunch. B. greater after lunch than before. C. the same before and after lunch.

the same before and after lunch.

A karate expert executes a swift blow and breaks a cement block with her bare hand. The magnitude of the force on her hand is A. zero. B. more than the force applied to the block. C. the same as the force applied to the block. D. less than the force applied to the cement block. E. need more information

the same force as the force applied to the block

When a boxer is moving away from a punch, the force experienced is reduced because A. momentum transfer is reduced. B. the force is less effective. C. the time of contact is increased. D. all of the above

the time of contact is increased.

The conservation of momentum is most closely related to Newton's A. first law. B. second law. C. third law.

third law

You do work on a cart loaded with groceries. If you do this work in one-third the usual time, you expend A. one third as much power. B. three times the usual power. C. the usual power. D. need more information.

three times the usual power

To catch a fast-moving softball with your bare hand, you extend your hand forward just before the catch and then let the ball ride backward with your hand. Doing this reduces the catching force because the A. relative velocity is more. B. relative velocity is less. C. time of catch is increased. D. time of the catch is decreased. E. none of the above

time of catch is increased

A 1-kg chunk of putty moving at 1 m/s collides and sticks to a 5-kg bowling ball initially at rest. The bowling ball and putty move with a momentum of A. more than 5 kg∙m/s. B. 1 kg∙m/s. C. 0 kg∙m/s. D. 5 kg∙m/s. E. 2 kg∙m/s.

1 kg*m/s

A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball initially at rest. After the putty sticks to the ball, both move with a combined momentum of A. less than 1 unit. B. 1 unit. C. more than 1 unit. D. not enough information

1 unit

Two billiard balls having the same mass roll toward each other at the same speed. What is the net momentum of the two-ball system? A. 0 kg∙m/s B. 10 kg∙m/s C. not enough information

0 kg*m/s

When a 100-kg astronaut ejects 0.1 kg of gas at a speed of 50 m/s from her propulsion pistol, her recoil speed is A. 50 m/s. B. 0.05 m/s. C. 0.5 m/s. D. 5.0 m/s.

0.05 m/s

A 2-kg rifle is horizontally suspended by a pair of strings so that recoil can be measured. The rifle fires a 0.001-kg bullet at a speed of 200 m/s. The recoil velocity of the rifle is about A. 0.001 m/s. B. 1 m/s. C. 0.1 m/s. D. 0.01 m/s. E. none of the above

0.1 m/s

Two identical freight cars roll without friction towards each other on a level track. One car rolls at 2 m/s and the other car rolls at 1 m/s. After the cars collide, they couple and roll together with a speed of A. 1.0 m/s. B. 0.5 m/s. C. 0.33 m/s. D. 0.67 m/s. E. none of the above

0.5 m/s

A 30-kg girl on friction-free roller blades pushes away a 25-kg boy also on roller blades at 1 m/s. The girl's speed is A. 0.45 m/s. B. 0.83 m/s. C. 0.55 m/s. D. 1.2 m/s.

0.83 m/s

Two identical gliders slide toward each other on an air track. One glider moves at 1 m/s and the other glider moves at 2 m/s. They collide, stick, and move at A. 1/3 m/s. B. 1/6 m/s. C. 3/4 m/s. D. 1.5 m/s. E. 1/2 m/s.

1/2 m/s

A 1-kg glider and a 2-kg glider both slide toward each other at 1 m/s on an air track. When they collide and stick, the combined-glider speed is A. 1.5 m/s. B. 1/2 m/s. C. 0 m/s. D. 1/6 m/s. E. 1/3 m/s.

1/3 m/s

A 1-kg chunk of putty moving at 1 m/s collides and sticks to a 5-kg bowling ball that is initially at rest in space. The bowling ball and putty are then set in motion with a speed of A. 1/4 m/s. B. 1/6 m/s. C. 1/5 m/s. D. none of the above E. not enough information

1/6 m/s

A 5-kg fish swimming at 1 m/s swallows an absent-minded 1-kg fish swimming toward it at 4 m/s. The speed of the larger fish after lunch is A. 1/5 m/s. B. 1/2 m/s. C. 3/2 m/s. D. 2/3 m/s. E. 1/6 m/s.

1/6 m/s

Consider gliders that slide friction-free along a horizontal air track. Glider A has a mass of 1 kg, a speed of 1 m/s, and collides with glider B, which has a mass of 5 kg and is at rest. If they stick upon collision the combined-glider speed will be A. 1/6 m/s B. 1/4 m/s. C. 1 m/s. D. 1/5 m/s. E. none of the above

1/6 m/s

It takes 40 J to push a large crate 4 m across a floor. The force exerted on the crate is A. 10 N. B. 4 N. C. 160 N. D. 1600 N. E. 40 N.

10 N

A melon is tossed straight upward with 100 J of kinetic energy. If air resistance is negligible the melon will return to its initial level with a kinetic energy of A. more than 100 J. B. 100 J. C. less than 100 J. D. need more information

100 J

What is the mass of a ball moving at 4 m/s with a momentum of 48 kg∙m/s? A. 12 kg B. 4 kg C. 192 kg D. 48 kg E. none of the above

12 kg

What is the speed of a 6-kg ball with a momentum of 72 kg∙m/s?A. 12 m/s B. 4 m/s C. 48 m/s D. 3 m/s E. none of the above

12 m/s

What is the mass of a ball moving at 3 m/s with a momentum of 48 kg∙m/s? A. 144 kg B. 4 kg C. 16 kg D. 12 kg E. none of these

16 kg

A shopping cart moves with a kinetic energy of 40 J. If it moves at twice the speed, its kinetic energy is A. 80 J. B. 40 J. C. 160 J. D. not enough information

160 J

A 2-kg mass that weighs 20 N has 40 J of potential energy relative to the ground. What is its height? A. 1 m B. 2 m C. 3 m D. 4 m E. none of the above

2 m

A 1000-kg truck moving at 10 m/s that brakes to a stop in 5 s has an average braking force of A. 2000 N. B. 1000 N. C. 4000 N. D. 5000 N. E. 3000 N.

2000 N.

What is the speed of a 4-kg ball with a momentum of 12 kg∙m/s?A. 12 m/s B. 3 m/s C. 4 m/s D. 48 m/s E. none of the above

3 m/s

A bow is drawn so that it has 40 J of potential energy. When the arrow is fired its kinetic energy is ideally A. more than 40 J. B. 40 J. C. less than 40 J.

40 J

A music console is pushed 2 m by a force of 20 N. The work done on the console is A. 80 J. B. 20 J. C. 40 J. D. 10 J. E. 2 J.

40 J

A 5-kg fish swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish at rest. The speed of the larger fish after lunch is A. 5/6 m/s. B. 1 m/s. C. 1/2 m/s. D. 6/5 m/s. E. 2/5 m/s.

5/6 m/s

A boxer punches a sheet of paper in midair from rest to a speed of 40 m/s in 0.05 s. If the mass of the paper is 0.01 kg, the force of the punch on the paper is A. 0.8 N. B. 80 N. C. 8.0 N. D. 0.08 N.

8.0 N.

A 2-kg mass weighs 20 N and is held 4 m above the ground. Its potential energy relative to the ground is A. 80 J. B. 8 J. C. 60 J. D. 20 J. E. none of the above

80 J

According to the impulse-momentum relationship Ft = change in mv, a falling bungee jumper has momentum which is reduced by the force F exerted by the bungee cord. If v is the speed of the jumper, then m in the equation is the mass of the A. jumper. B. ground below. C. cord. D. none of the above

A. jumper.

Which of these two collisions is more damaging; driving into a concrete wall with no "give," or colliding head-on with an identical car moving toward you at your same speed? A. collision with the car B. collision with the wall C. both the same

Both the same

According to the impulse-momentum relationship Ft = change in mv, a falling baseball hits a player with a force F. The t in the equation is the time A. the ball falls before hitting the player. B. of reflex as the player responds to being hit. C. of contact of the ball hitting the player. D. all of the above E. none of the above

C. of contact of the ball hitting the player.

The impulse-momentum relationship is a direct result of A. Newton's second law. B. Newton's first law. C. Newton's third law.

Newton's second law.

Which has greater kinetic energy: a car traveling at 30 km/h or another car of half the mass traveling at 60 km/h? A. The 30-km/h car B. The 60-km/h car C. both have the same kinetic energy

The 60-km/h car

An astronaut floating alone in outer space throws a baseball. If the ball moves away at 20 m/s, the astronaut will move in the opposite direction at A. a higher speed. B. a lower speed. C. 20 m/s. D. more information needed E. none of the above

a lower speed

Which of the following has the largest momentum relative to Earth? A. a tightrope walker crossing Niagara Falls B. a Mack truck parked in a lot C. a dog running down the street D. a pickup truck speeding along a highway

a pickup truck speeding along a highway

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, the contact time is about 10 times more than for a stiff-legged landing and the average force your body experiences is reduced by A. more than 10 times. B. about 10 times. C. less than 10 times.

about 10 times

A moving object has A. velocity. B. momentum. C. speed. D. energy. E. all of the above

all of the above

The force of a falling apple hitting the ground depends upon A. whether or not the apple bounces. B. the speed of the apple just before it hits the ground. C. the time of contact with the ground. D. all of the above

all of the above

The massive ram of a pile driver falling from rest strikes a pile with a speed that depends on the A. initial height of the ram. B. distance the ram falls. C. initial potential energy of the ram. D. all of the above

all of the above

Bronco's speed increases after he dives from a hovering helicopter. Relative to an observer in the helicopter Bronco's momentum A. decreases. B. remains unchanged. C. also increases.

also increases

When you simultaneously drop a light tennis ball and a heavy bowling ball, they hit the floor A. with the same force. B. at the same speed. C. with the same momentum. D. all of the above E. none of the above

at the same speed

If a monkey floating in outer space throws his hat away, the hat and the monkey will both move A. away from each other at the same speed. B. a short distance and then slow down. C. a short distance and then gain speed. D. away from each other, but at different speeds. E. quickly to a stop.

away from each other, but at different speeds

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the impulse is A. greater with the haystack. B. greater with the brick wall. C. both the same

both the same

While driving down the highway a lovebug spatters onto your windshield. Which undergoes the greater change in momentum during the time of contact? A. the lovebug B. your car C. both the same

both the same

While driving down the highway a lovebug spatters onto your windshield. Which undergoes the greater impulse? A. your car B. the lovebug C. both the same

both the same

While driving down the highway a lovebug spatters onto your windshield. Which experiences the greater force of impact? A. the lovebug B. your car C. both the same but with different consequences

both the same but with different consequences

A karate chop is more effective if one's hand A. bounces upon impact. B. extends the time upon impact. C. follows through upon impact.

bounces upon impact

Padded dashboards in cars are safer in an accident than non-padded ones because a person hitting the dash has a. increased time of contact b. decreased contact force c. both of these d. neither of these

c. both of these

A car traveling along the highway brakes to a stop. A greater braking force is required when the car has a. less stopping b. more momentum c. more mass d. all of the above e. none of the above

d. all of the above

An open freight car rolls friction-free along a horizontal track in vertically pouring rain. As water accumulates in the car, its speed A. decreases. B. increases. C. doesn't change.

decreases

When Freddy Frog drops vertically from a tree onto a horizontally-moving skateboard, the speed of the skateboard A. decreases. B. increases. C. neither decreases nor increases.

decreases

When bullets are fired in a forward direction from a fighter aircraft, the momentum of the aircraft A. is unchanged. B. decreases. C. increases.

decreases

Whereas impulse involves the time that a force acts, work involves the A. acceleration that a force produces. B. distance that a force acts. C. time and distance that a force acts.

distance that a force acts.

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is A. doubled. B. quadrupled. C. unchanged. D. zero.

doubled

Which has the greater momentum when moving? A. a bullet B. a container ship C. either of these depending on speed

either of these depending on speed

The force of air impact upon the sail of a boat is greater if the air A. encounters the sail head-on. B. encounters the sail at a grazing angle. C. bounces upon impact.

encounters the sail head-on

The unit kilowatt-hour is a unit of A. power. B. energy. C. momentum. D. time.

energy

When Jean standing on slippery ice catches her leaping dog Daisy, the momentum of both Jean and Daisy after the catch is A. greater than their combined momentum before the catch. B. somewhat less than their combined momentum before the catch. C. equal to their combined momentum before the catch.

equal to their combined momentum before the catch.

The force that accelerates a rocket in outer space is exerted on the rocket by the A. rocket's wings. B. rocket's engine. C. atmospheric pressure. D. exhaust gases. E. none of the above

exhaust gases

The total momentum of a flock of identical birds could be zero only if the birds are A. very tired and coming down to rest. B. flying in different directions. C. flying in the same direction. D. taking off from the ground.

flying in different directions

When Freddy Frog drops vertically from a tree onto a horizontally-moving skateboard, he doesn't slip off the skateboard because of A. friction between his feet and the board. B. inertia in motion. C. momentum change.

friction between his feet and the board.

A straw is used for a pea shooter. When you blow through the straw the speed of the emerging pea will be greater if the straw is A. cut in half. B. full length. C. either cut in half or full length.

full length

A heavy truck and a small car roll down a hill at the same speed and need to stop in the same amount of time. Compared with the force to stop the car, the force needed to stop the truck is A. greater. B. smaller. C. the same.

greater

When an apple falls to the ground, momentum is transferred to the ground. The momentum absorbed by the ground is A. greater than that of the apple whether or not bouncing occurs. B. greater if the apple bounces. C. negligible compared to the momentum of the apple. D. none of the above

greater than that of the apple whether or not bouncing occurs.

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the stopping force is A. greater with the brick wall. B. greater with the haystack. C. both the same

greater with the brick wall.

A clerk can lift containers a vertical distance of 1 m, or roll them up a 2-m-long ramp to the same elevation. With the ramp, the applied force needed is A. twice as much. B. half as much. C. the same.

half as much.

The speed of a bullet fired from a gun will be about the same as the speed of the recoiling gun A. when both velocity and momentum are conserved. B. when momentum is conserved. C. if the masses of the bullet and gun are equal. D. because velocity is conserved. E. none of the above

if the masses of the bullet and gun are equal.

A cannonball fired from a long-barrel cannon will have a greater muzzle velocity because the cannonball receives a greater A. force. B. impulse. C. both of these D. none of the above

impulse

The change in momentum of an object is equal to the A. change in its velocity. B. impulse that acts on it. C. object's mass times the force acting on it. D. force acting on it. E. all of the above

impulse that acts on it

Compared with falling on a wooden floor, a wine glass may not break when it falls on a carpeted floor because of A. longer time to stop. B. lesser impulse in stopping. C. both of these D. none of the above

longer time to stop

When a cannon fires a cannonball at a given speed, the smaller recoil speed of the cannon is due to differences in A. times. B. forces. C. momenta. D. masses.

masses

A heavy truck and a small truck roll down a hill. Neglecting friction, at the bottom of the hill the heavy truck has greater A. acceleration. B. momentum. C. speed. D. all of the above E. none of the above

momentum

An iron ball and wooden ball of the same size are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater A. acceleration. B. momentum. C. speed. D. all of the above E. none of the above

momentum

An object in motion is an object that has A. momentum. B. impulse. C. acceleration. D. all of the above E. none of the above

momentum

A cat and a mouse run along a road with the same kinetic energy. The faster runner is the A. mouse. B. cat. C. both run at the same speed D. not enough information

mouse

A fan attached to an ice sailcraft stalled on a windless day blows air into the sail that bounces backward upon impact. The boat A. moves, but in the opposite direction of the wind impact force. B. does not move by this wind impact. C. moves in the direction of the wind impact force.

moves in the direction of the wind impact force

An object that has kinetic energy must be A. at an elevated position. B. moving. C. falling. D. at rest. E. none of the above

moving

A 0.5-kg blob of clay moving at 2.0 m/s slams into a 4.0-kg blob of clay at rest. The speed of the two blobs stuck together after colliding is about A. 1.1 m/s. B. 2.5 m/s. C. 1.5 m/s. D. none of the above

none of the above

A sandbag is motionless in outer space. A second sandbag with 3 times the mass moving at 12 m/s collides with it and they both stick together and move at a speed of A. 6 m/s. B. 8 m/s. C. 4 m/s. D. 3 m/s. E. none of the above

none of the above

A 1-N-falling apple hits the ground with a force of A. 4 N. B. 1 N. C. 2 N. D. 10 N. E. not enough information

not enough information

Work is done by gravity on a bowling ball that rolls A. on a sloped surface. B. along a horizontal surface. C. both of these D. none of the above

on a sloped surface.

Consider a gun with a pellet that is more massive than the gun. The firing speed is greater for the A. recoiling gun. B. pellet. C. both are the same D. none of the above

recoiling gun

It is correct to say that impulse is equal to A. the force multiplied by the distance the force acts. B. momentum. C. the change in momentum. D. all of the above E. none of the above

the change in momentum

The distinction between impulse and force involves the A. time the force acts. B. mass and its effect on resisting a change in momentum. C. distance the force acts. D. difference between acceleration and velocity.

time the force acts

If you do work on an object in half the time, your power output is A. twice. B. the same. C. half.

twice

When you ride your scooter you have momentum. When you ride twice as fast you have A. four times the momentum. B. twice the momentum. C. almost twice the momentum. D. none of the above

twice the momentum

Power is defined as the A. work done multiplied by the time to do the work. B. work done divided by the time to do the work. C. force exerted multiplied by the distance moved. D. force exerted divided by the time of exertion. E. none of the above

work done divided by the time to do the work.

Recoil is noticeable if we throw a heavy ball while standing on a skateboard. If instead we go through the throwing motion but hold onto the ball, without friction effects our net recoil will be A. the same as before. B. zero. C. small, but noticeable.

zero