A force given by the relation `F=8t`, acts on a body of mass `2 kg`, initialiy at rest. Find the work done by this force on the body during first `2` seconds of its motion.

Options

A. `64J`
B. zero
C. `-64J`
D. none of these

Explanation

`F=3t`
`m.(dv)/(dt)=8t`
`m int_(0)^(v)dv=8 int_(0)^(t) dt`
`mv=4t^(2)`
or `m(dx)/(dt)=4t^(2)rArrdx=(4t^(2))/(m)dt=2t^(2)dt`
`W=intFdx=int_(0)^(2)(8txx2t^(2))dt=64J`