The 100-lb block slides down the inclined plane for which the coefficient of kinetic friction is 0.25 k = . it is moving at 10ft/s when it reaches the point a, 10ft from b along the inclined plane.

find a) (2pt) the change in potential energy of the block going from a to b.

b) (3pt) the work done against friction going from a to b, and the speed of the block at b.

c) (5pt) the maximum deformation of the spring  needed to momentarily arrest (stop) the motion of the block