A block of weight 4 kg is resting on a smooth horizontal plane. If it is struck by a jet of water at the rate of 2 kg `s^(-1)` and at the speed of 10 m s', then the initial acceleration of the block is

Options

A. `15ms^(-2)`
B. `10 ms^(-2)`
C. `2.5 ms^(-2)`
D. `1 ms^(-2)`

Answer

D

Explanation

`(dm)/(dt) = 2kg//s, v = 10 m//s `
`F = v (dm)/(dt) rArr ma = 10 xx 2`
`rArr a = (20)/(4) = 5m//s^(2)` .