Question

A 0.5-kg ball moving at 5 m/s strikes a wall and rebounds in the opposite direction with a speed of 2 m/s. If the impulse occurs for a time duration of 0.01 s, find the magnitude of the net force on the ball.

Answer 1

Answer: 350 N

Explanation:

Given

Mass of ball is $0.5\ kg$

Speed of ball after rebound is $v=2\ m/s$

Time period for impulse $t=0.01\ s$

Impulse imparted in equal to the change in the momentum of object

$\Rightarrow J=m(v-u)\quad [\text{u=speed of ball before collision}]\\\Rightarrow J=0.5\times \left(2-(-5)\right)\\\Rightarrow J=0.5\times 7\\\Rightarrow J=3.5\ N.s$

Impulse is the product of average force and duration of application

$\Rightarrow J=F_{avg}\cdot \Delta t\\\Rightarrow 3.5=F_{avg}\times 0.01\\\\\Rightarrow F_{avg}=350\ N$