Question

A cricket ball of mass $150g$ is moving with a velocity $12m{s}^{-1}$ and is hit by a bat so that the ball is turned back with a velocity of $20m{s}^{-1}$. If the duration of contact between the ball and bat is $0.01s$, find the impulse and the average force exerted on the ball by the bat.

Answer 1

Given:

Mass, m = 150 g = 0.15 kg

Velocity, u = 12 m/s

Velocity, v = 20 m/s

Time, t = 0.01 s

To find:

Impulse, J

Average force, F

Solution:

Initial momentum = mu = 0.15(12) = 1.8 Ns

Final momentum = mv = 0.15(20) = 3 Ns

Impulse = change in momentum = final momentum - initial momentum = 3 - 1.8 = 1.2 Ns

Also, $J=F\Delta t$

$\therefore F=\frac{J}{\Delta t}=\frac{1.2}{0.01}=120N$