PROBLEM 5: The upper block is attached to the ground as shown in the figure by a short rope. The coefficient of friction between the blocks is 0.25 while the angle of friction between the lower block and the horizontal ground is 30°. (a) Determine the tension in the rope, in N, when the lower block is about to move. (b) Determine friction force, in N, under the 900 N block when it is about to move. (c) Determine the horizontal force P, in N, required to initiate motion. 300 N P 900 N 30°

The crate pulled by a man as shown weighs 200 N. Supposed that the static friction coefficient between the contact surfaces is 0.25. Determine the following: a.) The value of angle alpha (ᾳ) to obtain the smallest possible value of the pulling force the man exerted so that the crate is on the verge of moving. b.) The smallest value of the pulling force the man exerted, c.) The normal reaction between the contact surfaces (Crate and Horizontal floor).

An arrangement of three boxes is shown in figure below. Box A weighs 25 N and rests on an inclined plane, while box B weighs 50 N and rests on a horizontal plane. The coefficient of friction between box A and the inclined plane is 0.3, and between box B and the horizontal plane is 0.4. The pulleys are all frictionless. Determine the range of weight of box C for which no motion will occur. Consider both sliding and tipping of boxes A and B. 0.6 m 0.75 m 25 N 5 A 4 C pome 0.8 m 0.6 m 50 N B 1.2 m

A 150lb man stands on a 60lb bar to which a cable is fixed at B. The cable passes over two fixed pegs with coefficients of friction indicated.  Assume that the arrangement of the pegs permits the cable to contact each peg over a total angle of 90-degrees (90-degrees per peg).  Assume that the normal force exerted by the man on the bar acts downward through A.  Find the largest force the man can exert on the cable and maintain the bar horizontal.