$(25$ Points$)$ Section $A$ is a steel GPa, $=0\mathrm{.}32$ tube with an outside diameter of $60$ mm and inside diameter of $50$ mm $.$ Section $B$ is a solid aluminum $(E=70$GPa,$v=0\mathrm{.}35)$ bar with a $50$ mm diameter over the first half of its length and $25$ mm the second half. Determine the following:

$[$a$]$ Normal stress in section A

$=156$MPa

$[$b$]$ Normal stress in section B $($middle section$)=134\mathrm{.}785MP?$

c$.)$ Normal strain in section $B($middle section$)$

$[$d$]$ Change in length of section $A=3\mathrm{.}126{10}^{-4}m$

$($e$)$ Change in diameter of section $B($middle section$)$