A block of mass `15 kg` is resting on a rough inclined plane as shown in figure ,The block is tied by a horizontal string which has a tension `50 N` The coefficient of friction of contact is

Options

A. `1//2`
B. `2//3`
C. `3//4`
D. `1//4`

Answer

A

Explanation

The string is under tension, hence there is limiting friction between the block and the plane
`sumF_(x)=0` implies `muN+50cos=150sin45^(@)` (i)
`sumF_(y)=0` implies `N=50sin45^(@)+150cos45^(@)` (ii)
Solving (i) and (ii), `mu=1//2` .