Thank you for reporting, we will resolve it shortly
Q.
A cricket ball of mass $0.25\, kg$ with speed $10 \,m/s^{-1}$ collides with a bat and returns with same speed within $0.01\, s$. The force acted on bat is
We have the cricket ball having a mass of $0.25\, kg$
and moving with a speed of $10 \,m / s$,
so the change in momentum would be equal to
$\Delta p=2 m v=2 \times 0.25 \times 10=5\, kg - m / s$ and
thus the force would be equal to
$F=\frac{\Delta p}{\Delta t}=\frac{5}{0.01}=500\, N$