(a) If the block reaches the bottom of the slope at 12.0 m/s, what is the average frictional force between the block and the surface of the slope?
(b) What is the kinetic cofficient of friction of the block on the slope?
(c) After reaching the bottom of the slope, the block continues to slide on the level ground of 30.0m before stopping, what is the kinetic coefficent of friction between the level ground and the block?