Two aluminium bars (E = 70 GPa) are attached to regid support at the left and a cross-bar at the end. An iron bar (E = 200 GPa) is at attached to the rigid support at the left and there is a gap b = 0.6 mm between the right end of the iron bar and cross-bar. The cross sectional area of each bar is A = 400 mm2 and L = 250 mm. If the cross bar is loaded with a load P = 250 kN, what are the normal stresses in the bars afterward?