You are lowering two boxes, one on top of the other, down the ramp shown in the figure(Figure 1)by pulling on a rope parallel to the surface of the ramp. Both boxes move together at a constant speed of 20.0cm/s . The coefficient of kinetic friction between the ramp and the lower box is 0.433, and the coefficient of static friction between the two boxes is 0.779.
What forceT do you need to exert to accomplish this?