Question

2.5 A ball moving with a velocity 20 m/sec has a mass of 50 gm. If collides against a wall normally and is rebounded normally with the same speed. If the time of impact of the ball and the wall is 40 mili seconds, the average force exerted on the wall in dynes is - [1] zero [3] 2.5 * 107 [2] 1.25 * 107 [4] 5 x 106​

Answer 1

Answer:

Change in velocity = 20 m/s – (-20 m/s) = 40 m/s

Change in momentum of ball = 0.05 * 40 = 2 kg-m/s

Average force = 2 / (40 * 0.001) = 50 N = 5 mega dynes