The pin-connected structure consists of a rigid bar abc, a solid bronze [e = 102 gpa, 14.3 × 10−6/°c] rod (1), and a solid aluminum alloy [e = 61 gpa, 23.6 × 10−6/°c] rod (2). bronze rod (1) has a diameter of 25 and aluminum rod (2) has a diameter of 16 mm. the bars are unstressed when the structure is assembled at 32°c. after assembly, the temperature of rod (2) is decreased by 40°c, while the temperature of rod (1) remains constant at 32°c. assume l1 = 290 mm, l2 = 490 mm, a = 210 mm, and b = 410 mm. determine the normal stresses , in both rods for this condition (positive if tensile, negative if compressive).