A block of mass `m` is placed at rest on a horizontal rough surface with angle of friction `phi`. The block is pulled with a force `F` at an angle `theta` with the horizontal. The minimum value of `F` required to move the block is

Options

A. `(F)/(M) ( cos phi - sin phi) - mu g`
B. `(mu F)/(M)cos phi`
C. `(F)/(M) ( cos phi + sin phi) - mu g`
D. `(F)/(M)sin phi`

Answer

c

Explanation

`N = Mg - F sin theta `

`a = (F cos theta - mu (Mg - F sin theta))/(M)`