Chapter 8, Problem 43P

The screw of the clamp has a square thread of pitch 0.16 in. and a mean diameter of 0.6 in. The coefficient of static friction between the threads is 0.4. Determine (a) the torque C0 that must be applied to the screw in order to produce a 28-lb clamping force at A; and (b) the torque required to loosen the clamp.

The two uniform sheets of plywood, each of length L and weight W, are propped as shown. If the coefficient of static friction is 0.5 at all three contact surfaces, determine whether the sheets will remain at rest.

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.

The 40-lb spool is suspended from the hanger GA and rests against a vertical wall. The center of gravity of the spool is at G and the weight of the hanger is negligible. The wire wound around the hub of the spool is extracted by pulling its end with the force P. If the coefficient of static friction between the spool and the wall is 0.25, determine the smallest P that will extract the wire.

Find the largest value of b/h at which the folding table is in equilibrium. The coefficients of static friction are 0.5 at A and 0.3 at C. Neglect the weight of the table.

The mass of the unbalanced disk is m, and its center of gravity is located at G. If the coefficient of static friction is 0.2 between the cylinder and the inclined surface, determine whether the cylinder can be at rest in the position shown. Note that the string AB is parallel to the incline.

The 3600-lb car with rear Wheel drive is attempting to tow the 4500-lb crate. The center of gravity of the car is at G, and the coefficients of static friction are 0.6 at B and 0.2 at C. Determine if the crate will slide.

The panel of weight W with its center of gravity at G is placed between vertical guides and released. Determine the largest height h for which the panel will not slide down due to binding at corners A and B. The coefficient of static friction between the panel and the guides is 0.5.

The 60-lb plank rests on a frictionless roller at A, and the 20-lb triangular support BD. Both bodies are homogenous. The coefficients of static friction are 0.4 at B and 0.3 at D. Determine the largest force P that can be applied to the plank without initiating motion.