For the plane truss shown in Figure P15–9, bar element 2 is subjected to a uniform tempe...

For the plane truss shown in Figure P15–9, bar element 2 is subjected to a uniform temperature rise of T = 10 ° C. Let E = 210 GPa, A = 12.5 cm² , and α = 12 × 10^–6/ ° C. What temperature change is needed in bars 1 and 3 to remove the stress due to the uniform temperature rise in bar 2? Show enough work to prove your answer. Use a longhand solution.