Question

A ball of mass m is dropped on to a floor from certain height, collision is perfectly elastic and the ball rebounds to the same height and again falls. Find the average force exerted by the ball on the floor during a long time interval.

• A. mg
• B. > mg
• C. < mg
• D. None of these

Answer 1

Answer: (A)

mg

Answer 2

∆p = m$\left\lbrack \sqrt{2gh} - \left( - \sqrt{2gh} \right) \right\rbrack$

= 2m$\sqrt{2gh}$; F_av = $\frac{\Delta p}{\Delta t} = \frac{n2m\sqrt{2gh}}{2n\sqrt{\frac{2h}{g}}}$