2.4-21 A rigid bar AB of a length L = 66 in. is hinged to a support at A and supported by two vertical wires attached at points C and D (see figure). Both wires have the same cross-sectional area (A = 0.0272 in-) and are made of the same material (modulus E = 30 x 10% psi). The wire at Chas a length / = 18 in. and the wire at D has a length twice that amount. The horizontal distances are c = 20 in. and d = 50in. (a) Determine the tensile stresses or and on in the wires due to the load P = 340 lb acting at end B of the bar. (b) Find the downward displacement 8: at end B of the bar. 2h h A C D B C. L PROBLEM 2.4-21