Find the least value of P required to cause the system of blocks shown to have impending motion to the left. The coefficient of friction under each block is 0.20. 50kN 15kN

The leather rein used to fasten the horse to the hitching rail weighs 3.5 oz per foot. The coefficient of static friction between the rail and the rein is 0.6. If a 34-lb force acting on the bridle is sufficient to restrain the horse, determine the smallest safe length L for the free end of the rein.

The block of weight W is pulled by the force P inclined at the angle to the horizontal. Find the smallest force P and the corresponding angle that would cause impending sliding of the block. The angle of static friction between the block and the ground is s.

The brake pads at C and D are pressed against the cylinder by the spring BF. The coefficient of static friction between each pad and the cylinder is 0.15. Find the smallest tension in the spring that would prevent the cylinder from rotating when the clockwise couple M=2200lbin. is applied. Neglect the weights of the members.