A block of wood of mass 0.5 kg is placed on a plane making `30^(@)` with the horizontal. If the coefficient of friction between the surfaces of contact of the body and the plane is 0.2. What force is required to keep the body sliding down uniform velocity.

Explanation

Force required to keep the body sliding down with constant velocity.
Given, m = 0.5 kg `g=9.8 ms^(-2)`,
`theta = 30^(@)`
`mu = 0.2`
`F=mg(sin theta - mu cos theta)`
= 1.6 N.