1.1. Newton's Cradle consists of a set of identical solid metal balls hanging by threads from a frame so that they are in contact with each other. 

A student initially pulls ball A to the side as shown. The student releases ball A and it collides with ball B.

(i) State the equation linking momentum, mass and velocity.

(1)

(ii) Each ball has a mass of 100 g. At the time of collision, ball A has a velocity of 3 m/s.

Calculate the momentum of ball A at the time of impact and give the unit. 

(3)

 Momentum = ........................... unit ....................

(iii) After the collision, ball A stops. Ball E moves away. The other balls remain still.

The momentum of ball E as it moves away is the same as the momentum of ball A at the time of impact. 

Suggest a reason for this. 

(1)

1.2. The student then releases balls A and B together as shown below.

Predict what will happen to the other balls after the collision and gives a reason for your answer.