Question

A block is at rest on an inclined plane whose elevation can be varied. The coefficient of static friction is μs= 0.350, and the coefficient of kinetic friction is μk= 0.160. The angle of elevation θ is increased slowly from the horizontal. At what value of θ does the block begin to slide (in degrees)?

Answer 1

It begins to move when at the point where the static friction force can no longer balance the component of gravity along the incline, i.e. when
\[mg\sin(\theta)=F_{s,\max}\]
Express \(F_{s,max}\) in terms of the normal force and solve.