Physics test

Suppose a gun were made of a strong but very light material. Suppose also that the bullet is more massive than the gun itself. For such a weapon

The target would be safer than the shooter

The difference between impulse and impact force included involves the

Time the force acts

A 50 kg moving + 20 m/s collides head-on with a stationary ball of mass 100 kg. The collision is elastic. What is the speed of each ball immediately after the collision

-6.7 m/s and +13.47 m/s

Two billiard balls having the same mass roll toward each other, each moving at the same speed. What is the combined momentum of the two balls

0 kg m/s

A 1-kg glider and a 2-kg glider both slide toward each other at 1 m/s on an air track. They collide and stick. The combined mass moves at

1/3 m/s

A 1-kg chunk of putty moving at 1 m/s collides with And sticks to a 5 kg bowling ball initially at rest. The bowling ball and putty then move with a momentum of

1/6 kg•m/s

A ball is moving at 4 m/s and has a momentum of 48 kg•m/s. What is the ball's mass

12 kg

A 5000-kg freight car moving at 2 m/s collides with a 10,000-kg freight car at rest. They couple upon collision and move away at

2/3 m/s

A 1000-kg car moving at 10 m/s brakes to a stop in 5 s. The average braking force is

2000 N

A 4 kg ball has a momentum of 12 kg•m/s. What is the ball's speed?

3 m/s

A rifle of mass 2 kg is suspended by strings. The rifle fires a bulletproof of mass 1/100 kg at a speed of 200 m/s. The recoil velocity of the rifle is about

-1 m/s

Two identical gliders slide toward each other on an air track. One moves at 1 m/s and the other at -2 m/s. They collide, stick, and moves at

-1/3 m/s

A 5-kg fish swimming at 1 m/s swallows an absent-minded 1-kg fish at rest. The speed of the larger fish after lunch is

5/6 m/s

A 5000-kg freight car runs 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 5000-kg car

6 m/s

The force on an apple hitting the ground depends on

All of these

The force that accelerates a rocket in outer space is exerted on the rocker by the

Exhaust gases

A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun

If the mass of the bullet equals the mass of the gun

Padded dashboards in cars are safer in an accident than non-padded ones because an occupant hitting the dash has

Increased the time of impact Decreased impact force

When you are in the way or a fast-moving object and can't get out of its way, you will suffer a smaller force of impact if you decrease its momentum over a

Long time

Two objects, A & B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, They reach the ground at the same time, but A has a greater

Momentum

1While floating motionlessly in a space station a 50 kg woman pushes a 100 kg man. He sails away at 1.0 m/s and she

Moves the opposite direction as the man at 2.0 m/s

You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in motion?

The bug

It is correct to say that impulse is equal to

The change in momentum

3While floating motionlessly in a space station a 50 kg woman pushes a 100 kg man. He sails away at 1.0 m/s. Which of the following is true?

The change in momentum of the women is equal to the man's change in momentum

2While floating motionlessly in a space station a 50 kg woman pushes a 100 kg man. He sails away at 1.0 m/s. Which of the following is true?

The force the woman puts on the man is equal to the force the man puts on the woman

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, you make the time of the legged landing. In this way the average force

about 1/10 as great

A sandbag is motionless in outer space. A second sandbag with 3 times the mass moving at 12 m/s collides with it. They stick together and move at a speed of

none of these

A 1-N apple falls to the ground. The apple hits the ground with an impact force of about

not enough information given to say

Recoil is noticeable if we throw a heavy ball while standing on roller skates. If instead we go through the motions of throwing the ball but hold onto it, our net recoil will be

Zero