The rigid bar ABCD of negligible weight is initially horizontal, and the stee rods attached at A and C are stress-free. The 20-kip load is then applied and th temperature of the steel rods is changed by AT. Find AT for which the stresses in th two steel rods will be equal. Use = 6.5 x 10-6/F and E = 29 106 psi for steel. 4 ft A 4 ft A=0.75 in.2 A = 0.5 in. B 3 ft 2 ft 2 ft 20 kips