The two cylindrical rod segments are fixed to the rigid walls such that there is a gap of 0.01 in. between them when t1 = 60°f. what larger temperature t2 is required in order to just close the gap? each rod has a diameter of 1.25 in. determine the average normal stress in each rod if t2=300°f. take αal = 13(10-6)/°f, eal = 10(103) ksi, (σy)al = 40 ksi, αcu = 9.4(10-6)/°f, ecu = 15(103) ksi, and (σy)cu = 50 ksi.