Chapter 8, Problem 58P

1. If the spring is compressed a distance 6 and the coefficient of static friction between the tapered stub S and the slider A is sA, determine the horizontal force P needed to move the slider forward.The stub is free to move without friction within the fixed collar C. The coefficient of static friction between A and surface B is µAB. Neglect the weights of the slider and stub. Given: 8 = 60 mm HsA = 0.5 HAB = = 0.4 N k = 300 e = 30 deg B

The rope running over two fixed cylinders carries the 4-kg mass at one end. Determine the force P that must be applied to the other end to initiate motion. The coefficient of static friction between the rope and the cylinders is 0.15. 150 mm 150 mm 400 mm 4 kg O 64.1 N O 63.1 N 65.1 N O 62.1 N

If the center of gravity of the stacked tables is at G, and the stack weighs 100 lb, determine the smallest force P the boy must push on the stack in order to cause movement. The coefficient of static friction at A and B is s = 0.3. The tables are locked together. Answer: P =

If each box weighs 150 lb, determine the least horizontal force P that the man must exert on the top box in order to cause motion. The coefficient of static friction between the boxes is μs = 0.54, and the coefficient of static friction between the box and the floor is μ's = 0.24.

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?

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 fork lift has a weight of 2,400 lb and a center of gravity at G. If the rear wheels are powered, whereas the front wheels are free to roll, determine the maximum number of 300-lb crates the fork lift can push forward. The coefficient of static friction between the wheels and the ground is μw = 0.4 and between the each crate and the ground μc = 0.35. 2.5 ft 1.25 ft -3.50 ft- XIXIX

The spool of wire having a weight of 300 lb rests on the ground at B and against the wall at A. Determine the 3 ft normal force acting on the spool at A if P = 300 Ib. The coefficient of static friction between the spool and the ground at B is µ, = 0.35. The wall at A is smooth. ift B.

The masses of the box at right is 30 kg. The coefficient of static friction between each box and the inclined surface is µs = 0.2. If a = 40°, determine a. The minimum value of the mass at the left to maintain equilibrium. b. The maximum value of the mass at the left to maintain equilibrium. 100 30°