The $\quad$ C83400-red-brass rod $A B$ and $2014-\mathrm{T} 6-$ aluminum rod $B C$ are joined at the collar $B$ and fixed connected at their ends. If there is no load in the members
when $T_{1}=50^{\circ} \mathrm{F}$, determine the average normal stress in each member when $T_{2}=120^{\circ} \mathrm{F}$. Also, how far will the collar be displaced? The cross-sectional area of each member is 1.75 in $^{2}$.