Question

A ball of mass 0.5 kg collides with a wall at a speed of 15.0 ms−1 and bounces back with a speed of 12.5 ms−1 . If the average force exerted by the ball is 1100 N calculate the impulse and the time for which the collision lasted.

Answer 1

$15.0 \times 1100 \div 12.5$

Answer 2

Impulse is defined as force applied to a particle for a certain period of time.

I = FΔt

I=ΔP =mΔV

I=0.5×(-12.5-15)Kg.m/s

 =13.75 K gm/s

Negative sign shows that force on the wall is opposite to force on the ball.

Again,

I=FΔT

Thus time=I/F=13.75/1100=0.0125 second.