3. The coefficient of friction between the block of mass mā = 3 kg and the surface in the figure is Ī¼ā = 0.4. The system starts from rest. What is the speed of the ball of mass mā = 5 kg when it has fallen 1.5 m.
4. A 10-kg block is released from rest at point A in the figure below. The track is frictionless except for the portion between point B and C, which has a length of 6 m. The block travels down the track and stopped by friction at point C. Determine the coefficient of kinetic friction between the block and the rough surface between points B and C.