Chapter 8, Problem 55P

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.

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 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 two homogeneous bars AB and BC are connected with a pin at B and placed between rough vertical walls. If the coefficient of static friction between each bar and the wall is 0.25, determine the largest angle 6 for which the assembly will remain at rest.

The 600-lb cable spool is placed on a frictionless spindle that has been driven into the ground. If the force required to start the spool rotating is F = 160 lb, determine the coefficient of friction between the ground and the spool. Neglect the diameter of the spindle compared to the diameter of the spool.

Force P is applied to the end of a rope being used to hold the 50-lb block on the 20° incline. The coefficient of static friction between the block and the incline is u. = 0.30. Determine the largest value of P for which the block is in equilibrium and will not begin to move up the incline when 0 = 15°. Hs = 0.30 20° The solution to this problem requires a free-body diagram of the block, and a sketch of the coordinate system used. Use the components of the forces with EF = 0 and EF, = 0 to y apply ΣF=0.

The man is trying to push the homogeneous 20-kg ladder AB up a wall by applying the horizontal force P. Determine the smallest value of Pthat would move the ladder. The coefficient of static friction between the ladder and both contact surfaces is 0.3. 1.5 m 2 m Note that h = 5 m

The drum has a weight of 110 lb and rests on the floor for which the coefficient of static friction is μs = 0.30. Assume the center of gravity of the drum is located at its center. Pt. A : If a = 3 ft and b = 4 ft, determine the smallest magnitude of the force P that will cause the drum to start sliding.   Pt. B: If a = 3 ft and b = 4 ft, determine the smallest magnitude of the force P that will cause the drum to start tipping. Pt. C : Based on the results in the previous two parts, the impending motion of the drum is....   Slipping or Tipping?

4. The 5-kg cylinder is suspended from two equal-length cords. The end of each cord is attached to a ring of negligible mass, which passes along a horizontal shaft. If the coefficient of static friction between each ring and the shaft is µ,=0.5, determine the greatest distance d by which the rings can be separated and still support the cylinder. 600 mm 600 mm