Physics - Center of Mass Question with Solution | TestHub

According to the impulse-momentum theorem, the impulse (change in momentum) is equal to the average force multiplied by the time duration of the force: $\vec{J}=\Delta \vec{p}={\vec{F}}_{avg}\Delta t$.

When catching a ball, the change in momentum ($\Delta \vec{p}$) of the ball is fixed (from its initial momentum to zero). By pulling his hands backward, the cricketer increases the time of impact ($\Delta t$).

Since $\Delta \vec{p}$ is constant, an increase in $\Delta t$ must result in a decrease in the average force (${\vec{F}}_{avg}$) exerted by the ball on the hands, thereby reducing the impact and preventing injury. Both A and R are true, and R correctly explains A.