(Solved): 36. The aluminum rod has a diameter of 0.5 in. and is attached to the rigid supports at A and B whe ...

36. The aluminum rod has a diameter of 0.5 in. and is attached to the rigid supports at $A$ and $B$ when $T_1=80^{?}\mathrm{F}$. If the temperature becomes $T_2=100^{?}\mathrm{F}$, and an axial force of $P=1200\mathrm{lb}$ is applied to the rigid collar as shown, determine the reactions at $A$ and $B.{?}_{al}=$ $12.8\left(10^{?6}\right)/?\mathrm{F},E_{al}=10.6\left(10^6\right)\mathrm{psi}$. 37. The aluminum rod has a diameter of 0.5 in. and is attached to the rigid support at $A$ and $B$ when $T_1=80^{?}\mathrm{F}$. Determine the force $\mathbf{P}$ that must be applied to the rigid collar so that, when $T_2=50^{?}\mathrm{F}$, the reaction at $B$ is zero, ${?}_{al}=12.8\left(10^{?6}\right)/\mathrm{oF}$, $E_{al}=10.6\left(10^6\right)\mathrm{psi}$.