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Momentum Questions

Q2. A girl kicks a ball along the ground at a wall 2.0 m away. The ball strikes the wall normally at a velocity of 8.0 ms-1 and rebounds in the opposite direction with an initial velocity of 6.0 ms-1. The girl, who has not moved, stops the ball a short time later.

 

(a) Explain why the final displacement of the ball is not 4.0 m.

(1 mark)

(b) Explain why the average velocity of the ball is different from its average speed.

(2 marks)

(c) The ball has a mass of 0.45 kg and is in contact with the wall for 0.10 s. For the period of time the ball is in contact with the wall,

(i) calculate the average acceleration of the ball.

(ii) calculate the average force acting on the ball.

(iii) state the direction of the average force acting on the ball.

(5 marks)

(Total 8 marks)