A crate of mass 30 kg is lying on a 30 incline as shown in the sketch. A steel ball of mass 20 kg is attached to the crate with a rope. The rope is going over a frictionless pulley. Calculate: a. The static friction coefficient so that the block moves up with constant velocity. b. The kinetic friction coefficient so that the block moves up with an acceleration of 30 cm/s2.

9. A crate of mass 30kg is lying on a 30 incline as shown in the sketch. A steel ball of mass 20kg is attached to the crate with a rope. The rope is going over a frictionless pulley. Calculate: a. The static friction coefficient so that the block moves up with constant velocity. Ans: (0.19) b. The kinetic friction coefficient so that the block moves up with an acceleration of 30cm.s22. Ans: (0.13)