Two sheets of plywood A and B lie on the bed of the truck They have the same weight W, and the coefficient of static friction between the two sheets of wood and between sheet B and the truck bed is g. (a) If you apply a horizontal force to sheet A and apply no force sheet B to move? What force is necessary to cause sheet A to start to sheet B, can you slide sheet A off the truck without causing moving? (b) If you prevent sheet A from moving by exerting a horizontal force on it, what horizontal force on sheet B is necessary to start moving? A B