A spring is not stretched or compressed at the point z = 0. A block of mass, m, pushed against the spring to the point x = -A. The block is released from rest and slides on a frictionless surface. At the point marked x = B the surface changes and the coefficient of friction between the block and the surface becomes u. At t = 0, defined to be the instant that the block reaches the point = B, a force acts on the block which points to the left and has magnitude t. At what time will the block come to rest? Immy X = -A K=O Free Body Diagram (If appropriate). Law or Definition 8