Assume E$\_($A$)=$E$\_($B$)=3\mathrm{.}2$ xx$10^(4)$ksi$,$E$\_($C$)=1\mathrm{.}6$ xx$10^(4)$ksi$,$alpha$\_($C$)=1$xx$10^(-7)//^($@$)$F$,$ and all posts

have a cross$-$sectional area of $16i{n}^2.$ If post $C$ is heated by $160F,$ determine

the average normal stress developed in post $A?$