A ball of mass `m` falls vertically to the ground from a height `h_1` and rebound to a height `h_2`. The change in momentum of the ball on striking the ground is.

Options

A. `mg(h_(1) - h_(2))`
B. `m (sqrt(2 gh_(1)) +sqrt(2 gh_(2)))`
C. `m sqrt(2g (h_(1) + h_(2)))`
D. `m sqrt(2 g) (h_(1) + h_(2))`

Answer

B

Explanation

`u = sqrt(2 gh_(1)) , v = sqrt(2 gh_(2)) `
`Delta p = m(v +u)`
` = m(sqrt(2 gh_(2)) + sqrt(2 gh_(1)))`