ch 6

A tiny gun made of a strong but very light matieraial fires a bullet more massive than the gun itself. For such a weapon A. The target would be safer than the shooter B. Recoil problems would be lessend C. Conservation of energy would not hold D. Conservation of momentum would not hold

A

The speed of a 4 kg woth a momentum of 12 kg m/s is A. 3 B.4 C. 12 D. 48

A

Two billard balls having the same mass and speed roll toward each other. What is their combined mommentum after the meet? A. Zero B. Half the sum of their original momentum C. Twice the sum of their original momentums D. Need more information

A

Two identical gliders slide toward each other on air track. One moves at 1 m/s and the other 2 m/s. They collide, strick, and moves at A. ½ B. ⅓ C. ⅙ D. ¾

A

When bullets are fored from an airplane in the forwars direction, the momentum of the airplane is A.Decreased B. Unchanged C. increased

A

A karate chop is more effective if one's hand A. Follows through upon impact B. Bounces upon impact C. Extends the time upon impact

B

An astronat floating alone in outer space throws a baseball. If the ball moves away at 20 m/s/ the atronaut will A. Move in the opposite direction at 20 m/s B. Move in the opposite direction at a lower speed C. Move in the opposite direction at a higher speed

B

An open freight car rolls friction free along a horizontal track in a pourong rain that falls vertically. As water accumulution in the car, the car's speed A. Increase B. Decrease

B

The average braking force of a 1000 kg car moving at 10 m/s braking to a stop on 5 s is A.1000N B. 2000 N C.3000 N D. 4000 N

B

Two 5000 kg rail cars roll without friction toward each other on a level track they collide, couple, and roll together with a combined momentum of A. Zero B. 5000 c. 10000

B

Two identical freight cars roll without friction toward each other on a leve, track they collide, couple together, and roll away in the direction of A.Slower car B. The faster car C. Neither

B

When a boxer is moving away from a punch, the force experiened is reduced becase A. Momentum transfer is reduced B The time of contact is inceased C The force is less effective D All of the above

B

A 5kg fish swimming at 1 m/s swallows an absent minded 1 kg fish at rest the speed of the larger fish after lunch is A. ½ B. ⅖ C. ⅚ D. 6/5

C

The change in momentum that occurs when a 1.0 kg ball traveling at -4.0 m/s strikes a wall and bounces back at 2 m/s is A. 2 B. 4 C. 6 D. 8

C

To catch a fast-moving ball, you extedn your hand forward befor contact with the balland let it ride backward in the direction of the balls motion. Doing this reduces the force of contact on your hand principally becase the A. Force of contact is reduced b. Relative velocity is less c. Time of contact is increased d. Time of contact is decreased

C

A 2kg rifle that is suspend by strungs by strings fores a .01 kg bullet at 200 m/s. The recoil velocity of the rifle is about A. .001 B. .01 C. .1 D. 1

D

A car traveling along the highway brakes to a stop over a certain distence. More braking force is required if the car has A.More mass B. More momentum C. Less stopping distance D. All of the above

D

The force on a dropped apple hitting the ground depends upon A. The speed of the apple just before it hits B. The time of contact with the ground C. Whether or not the apple bounces D. All of the above

D

The force that acceletration a rocket in outer space is exerted on the rocket by the A. Rockets nose cone B. Rockets wings C. Air pressure D. Exhaust gases

D

Freddy frog drop vertically from a tree onto a horizontally-moving skateboard. The reason he doesnt slip off the skateboard is due to A. Inertia B. Momentum C. Friction ntwn feet and board

c