A ball of mass 800g moving horizontally with a speed of 5m/s hits a vertical wall and rebounds with the same speed. The impulse experienced by the ball is?

A.

0kgm

B.

2kgm/s

C.

4kgm/s

D.

8kgm/s

Correct answer is D

Initial momentum = (0.8) × (5)

 = 4.0kgms\(^{-1}\)

  Final momentum

  = (0.8) × (– 5)

 = – 4.0kgms\(^{-1}\)

  Impulse on ball

  = Change in momentum

 = 4.0 – (– 4.0)

  = 8.0.0kgms\(^{-1}\)