Use Newton’s second law of motion to explain the following:

A cricketer pulls his hands back while catching a fast moving cricket ball.

Let u be the velocity of the ball of mass m, when it reaches the hands of the player catching it.

The initial momentum of the ball = mu

If the cricketer does not pull his hands and stops the ball as soon as it touches his hands, he uses very little time (t₁) to stop the ball.

Then, the force exerted by the ball on the hands of the cricketer is —

F = $\dfrac{\text {Change in momentum}}{\text {Time interval}}$ = $\dfrac{mu}{t_1}$

But if the cricketer pulls back his hands along with the ball, he takes a much longer time t₂ to stop the ball.

The force now exerted by the ball on his hands is F₂ = $\dfrac{mu}{t_2}$

Since, t₂ > t₁, therefore, F₂ < F ₁ or force exerted on the hands of cricketer by the fast moving ball is less when he withdraws his hands. Thus cricketer avoids the chances of injury to his palms by withdrawing his hands along with the ball while catching it.