A ball of mass m is dropped onto a floor from a certain height. The 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.

Explanation

A ball of mas m is dropped to a floor from a cetain height let h
`:. v_1=sqrt(2gh)`
`v_1=0`
`v_2=-sqrt(2gh)`
`v_2=0`
`:. Rate of change of velocity
F=(mxxw2sqrt(2gh))/t`
`:. V=sqrt(2hg)s=h, u=0`
`rarr sqrt(2gh)=gt`

`t=sqrt(2h)/g`
`:. Total time =2sqrt(2h)/g`
`:. F=(mxx2sqrt(2gh))/(2sqrt((2h)/g))=mg`