A body of mass `M` is resting on a rough horizontal plane surface the coefficient of friction being equal to `mu` At `t = 0` a horizontal force `F = F_(0) t` starts acting on it , where `F_(0)` is a constant find the time T at which the motion starts?

Options

A. `mu Mg//F_(0)`
B. ` mg// mu F_(0)`
C. `muF_(0)Mg`
D. None of these

Answer

a

Explanation

`f_(1) = mu Mg` if motion does not then

`f = F= F_(0)t`
Motion will start when `f = f_(1)`
`rArr F_(0)T = mu Mg rArr T = (mu Mg)/(F_(0))`