The force required to just move a body up the inclined plane is double the force required to just prevent the body from sliding down the plane. The coefficient of friction is `mu`. If `theta` is the angle of inclination of the plane than `tan theta` is equal to

Options

A. `mu`
B. `3 mu`
C. `2 mu`
D. `0.5 mu`

Answer

B

Explanation

`F_(1) = mg sin theta + mu mg cos theta`
`F_(2) = mg sin theta - mu mg cos theta`
Given than `F_(1) = 2F_(2)`
:. `(mg sin theta + mu mg cos theta) = 2(mg sin theta - mu mg cos theta)`
On solving, we get `tan theta =3 mu`