2.94 The elastic strip with a cutout is of length L, width b, and thickness t. Derive the expression for the elongation of the strip caused by the axial load P. 2.95 The aluminum bar of cross-sectional area 0.6 in.2 carries the axial loads shown in the figure. Compute the total change in length of the bar given that E = 10 x 10 psi. 6000 lb -0.4 L $0.6b P FIG. P2.94 4000 lb 7000 lb 5000 lb 3 5 ft 4 ft FIG. P2.95 4 ft Aluminum E = 10 x 10 psi 6 ft Steel E=29 x 10 psi 3 ft 6 ft- 10 1.0 ft FIG. P2.96 2.96 The uniform beam of weight W is to be supported by the two rods, the lower ends of which were initially at the same level. Determine the ratio of the areas of the rods so that the beam will be horizontal after it is attached to the rods. Neglect the deformation of the beam. 2.97 A round bar of length L, modulus of elasticity E, and weight density y tapers uniformly from a diameter 2D at one end to a diameter D at the other end. If the bar is suspended vertically from the larger end, find the elongation of the bar caused by its own weight. 2.98 The timber member BC, inclined at angle 0 = 60 to the vertical, is supported by a pin at B and the 0.75-in.-diameter steel bar AC. (a) Determine the cross-sectional area of BC for which the displacement of C will be vertical when the 5000-lb force is applied. (b) Compute the corresponding displacement of C. The moduli of elasticity are 1.8 106 psi for timber and 29 10 psi for steel. Neglect the weight of BC. 2.99 The collar B is welded to the midpoint of the cylindrical steel bar AC of length 2L. The left half of the bar is then inserted in a brass tube and the assembly is placed between rigid walls. Determine the forces in the steel bar and the brass tube when the force P is ap- plied to the collar. Neglect the deformation of the collar and assume (EA)st = 3(EA) br L L P B A FIG. P2.99 4 -7 ft FIG. P2.98 5000 lb