Find out the acceleration of the block. If the block is initially at rest.

Explanation

(FBD of the block excluding friction)

`N=10 gcos37^(@)=80N`
Now, `0 le f_(s) le muN`
`0 le f_(s) le 0.5 times 80`
`therefore f_(s) le 40N`

We will put value of f in the last i.e. in the direction opposite to resultant of other forces. f acts down the incline and its value is of = 75 – 60 = 15 N So acceleration is zero