Chapter 8, Problem 2P

The man has a mass, m =. 40 kg. He plans to scale the vertical crevice using the method shown. If the coefficient of static friction between his shoes and the rock is µ = 0.4 and between his backside and the rock is µ = 0.3, determine the smallest horizontal force his body must exert on the rocks in order to do this.

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

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 10-kg block is placed in an incline as shown. If the coefficient of static friction is 0.4, determine the minimum force P required to keep the block from sliding down

Determine the smallest horizontal force P required to lift the 100-kg cylinder. The coefficient of static friction at the contact points A and B are 0.6 and 0.2, respectively. The coefficient of static friction between the wedge and the ground is 0.3.

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 pushes on the roller with force P through a handle that connects to the central axle of the roller. If the coefficient of static friction between the 49-lb roller and the floor is s = 0.22, determine the maximum force Pthat can be applied to the handle, so that roller rolls on the ground without slipping. Assume the roller to be a uniform cylinder. Please pay attention: the numbers may change since they are randomized. Your answer must include 2 places after the decimal point, and proper unit. Take g = 32.2 ft/s2. 1.5 ft 30° Your Answer: Answer units

Determine the coefficient of static friction between the friction pad at A and ground if the inclination of the ladder is 0 =60° and the wall at B is smooth when the 82-kg man climbs up the leader and stops at the position shown after he senses that the leader is on the verge of slipping. The center of gravity for the man is at G. Neglect the weight of the leader.

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 P that would move the ladder. The coefficient of static friction between the ladder and both contact surfaces is 0.3.