**Answer the questions **

1. What is the value of the momentum of a 10 kg ball running down a bowling alley at a speed of 5 m/s?

2.** **Can you show that the change in momentum is +2mv?

3. The ball has a mass of 200 g, and the *value* of its velocity throughout remains 6 m/s. What is the change in momentum?

4. The diagram shows two cars at a fairground, before and after bumping into each other. One car and driver has a total mass of 500 kg, while the other car and driver has a total mass of 400 kg.

(a) What is (i) the total kinetic energy before the collision;

(ii) the total kinetic energy after the collision.

(iii) the total loss in kinetic energy.

(b) Is this an elastic collision? Explain your answer. **ANSWER**

5. A second collision is shown below:

What is the speed of the 500 kg car after the collision? **ANSWER**

**6. **A bullet of mass 45 g is travelling horizontally at 400 m/s when it strikes a wooden block of mass 16 kg suspended on a string so that it can swing freely. The bullet is embedded in the block.

Calculate:

a) The velocity at which the block begins to swing;

b) The height to which the block rises above its initial position;

c) How much of the bullets kinetic energy is converted to internal energy.**ANSWER**__ __

7. Can you explain how the formula *F = **p/**t* is consistent with Newton II? **ANSWER**

**8.** A car is involved in a collision in which it is brought to a standstill from a speed of 24 m/s. The driver of mass 85 kg is brought to rest by his seat belt in a time of 400 ms.

a) Calculate the average force exerted on the driver by his seat belt.

b) Compare this force to his weight and hence work out the g-force

c) Comment on the likelihood of serious injury.**ANSWER**

**Now try ****Topic 7 Test**

Presentations: __Momentum__

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