block A, with a weight w, slides down an inclined plane S of slope angle 37.0 degree at a...

block A, with a weight w, slides down an inclined plane S of slope angle 37.0 degree at a constant velocity while the plank B, also having weight w, rests on top of A. The plank is attached by a cord to the top of the plane. (a) draw a diagram of all the forces acting on block A.(b) if the coeffient of kinetic friction is the same between the surfaces A and B and between S and A, determine its value.