Asmall block of mass m is released from rest at point a at the top of a frictionless quarter-circular slide of radius r. it slides down to point b and across a rough horizontal surface. after sliding a distance l to point c, the block encounters a spring of spring constant k, and compresses it a distance d before coming to rest at point p. the surface is rough all the way from point b to point p. derive an expression for the coefficient of kinetic friction between the floor and the block, in terms of relevant system parameters.