The displacement x in meters of a particle of mass m kg moving in one dimension under the action of a force is related to the time t in seconds by the equation `t=sqrtx+3`, , the work done by the force (in J) in first six seconds is :-

Options

A. 18 m
B. zero
C. 9 m/2
D. 36 m

Answer

B

Explanation

`t=sqrtx+3`
`x=(t-3)^(2)`
`x=t^(2)-6t+9`
`V=(dx)/(dt)=2t-6`
`t=0" "u=-6`
`t=6" "v=12-6=6`
`W=(1)/(2)xxm|36-36|=0`