1. A railroad diesel engine weighs six times as much as a freight car.

If the diesel engine coasts at 5 kmh into a freight car that is initially at rest, find the speed of the coupled engine and car.

Express vour answer with the appropriate units

2. A car carrying a 75-kg crash-test dummy drives into a wall at 31 ms and is brought to rest in 0.1 s.

What is the average force exerted by the seat belt on the dummy?

Express your answer with the appropriate units

3. In a movie, the hero jumps straight down from a bridge onto a small boat that continues to move with no change in velocity. What physics is being violated here?

4. What impulse occurs when the same force of 12 N acts on the cart for 2.0 s twice?

Express your answer with the appropriate units.

5. In which type or kind of collision is momentum conserved: elastic or inelastic?

Momentum is conserved in elastic and inelastic collisions.

Momentum is conserved in neither elastic nor inelastic collisions.

Momentum is conserved only in elastic collisions.

Momentum is conserved only in inelastic collisions.

6.

A 2.0-kg blob of play dough moving at 5 m/s slams into a 2.0-kg blob of play dough at rest. Find the

speed of the two stuck-together blobs immediatelv after colliding

Express your answer with the appropriate units.

7.

What impulse occurs when an average force of 5.0 N is exerted on a cart for 2.4 ?

Express your answer with the appropriate units.

8.

What is the momentum of a 7.0-kg bowling ball rolling at 2.0 m/s?

9.

Rolling railroad car A makes a perfectly elastic collision with railroad car B of the same mass

After the collision, car A is at rest. Justify your answer.

How does the sneed of car B compare with the initial speed of car AS

The speed of car B is half the initial speed of car A

The speed of car B is zero.

The speed of car B is twice the initial speed of car A

The speed of car B is equal to the initial speed of car A

10.

What does it mean to say that momentum is conserved?

It means the net momentum is zero.

It means momentum is zero.

It means momentum does not change.

It means the change in momentum is equal to the impulse