FIGURE P8.54 shows a small block of mass m sliding around the inside of an L-shaped track

Question:

FIGURE P8.54 shows a small block of mass m sliding around the inside of an L-shaped track of radius r. The bottom of the track is frictionless; the coefficient of kinetic friction between the block and the wall of the track is Î¼_k. The block€™s speed is v₀at t₀= 0.
Find an expression for the block€™s speed at a later time t.

Bottom is frictionless FIGURE P8.54