9. Knowing that the coefficient of friction between the 15-kg block and the incline is us = 0.25, detemine (a) the smallest value of P required to maintain the block in equilibrium, (b) the corresponding value of ß. (P=108.8 N, ß=46°) 15 kg 60°

A 6.5-m ladder AB leans against a wall as shown. Assuming that the coefficient of static friction μs is the same at A and B, determine the smallest value of μs for which equilibrium is maintained.

A 12° wedge is used to spread a split ring. The coefficient of static friction between the wedge and the ring is 0.30. Knowing that a force P with a magnitude of 120 N was required to insert the wedge, determine the magnitude of the forces exerted on the ring by the wedge after insertion.

The axle of the pulley is frozen and cannot rotate with respect to the block. Knowing that the coefficient of static friction between cable ABCD and the pulley varies between 0.0 and 0.55, determine (a) the corresponding values of 0 for the system to remain in equilibrium, (b) the corresponding reactions at A and D, and (c) plot 8 versus the coefficient of friction. 60P B E 0 WD 60° 200 N