Work done in time t on a body of mass m which is accelerated from rest to a speed v in time `t_(1)` as a function of time t is given b

Options

A. ` (1)/(2) m (v)/(t_1)t^(2) `
B. ` m ( v)/(t_1) t^(2) `
C. ` (1)/(2) ((mv)/(t_1))^(2) t^(2) `
D. ` (1)/(2) m (v^(2))/(t_1^(2))t^(2) `

Answer

D

Explanation

Work done ` = F xx s = ma xx (1)/(2) at^(2) [" From " = ut +(1)/(2) at^(2) ]`
` therefore W = (1)/(2) ma^(2) t^(2) = (1)/(2) m ( (v)/( t_1)) ^(2) t^(2) [" As " a= (v)/(t_1)]`