Bars (1) are made of steel [E = 30,000 ksi], and bar(2) is made of an aluminum alloy [E = 10,000 ksi].All bars have cross-sectional areas of A = 1.25 in.2 and are unstressed when P is zero. When load P is applied, the strain in bar (2) is found to be 1200x10-6 in./in. Determine the normal stress in bars (1). Use dimensions a = 12 ft and b = 18 ft.

Fig: 1

Fig: 2