The structure in Figure 2.1 consists of a frame, two pulleys, one at B (1.6ft in diameter) and another at C (0.6ft in diameter), and two wires (E-F and G-D).

The 11-ft-long frame is pinned to a wall bya single shear pin at A. The dimension of each segment in the frame is given in the figure. The two wires are attached to F, G, and D, and subjected to a downward vertical force of 75 lb at E. Note that the pulleys at B and Care assembled to the frame by double shear pins. The diameters of wires E-F and G-D are 1 in and 1.5 in, respectively. a) Find normal force, shear force and bending moment diagrams for the straight section A-Bin the frame. b) Determine the diameters of pins at A, B, and C so that their average shear stresses are the same (10,000 psi).