A copper bar with a rectangular cross section is held without stress between rigid supports $($see figure$).$Subsequently, the temperature of the bar is raised $50\backslash$deg C$.$

$1)$ Determine the stresses on all faces of the element A and B$.$

$($Assume $\backslash$alpha $=17\mathrm{.}5106/\backslash$deg C and E $=120$ GPa.$)$

$2)$ Show the stresses from in part $($a$)$ on sketches of the elements.

$3)$ If the shear stress at B is known to be $48$ MPa at some inclination $\backslash$theta $,$ find angle $\backslash$theta $.$

$4)$ Show the stresses from in part $($c$)$ on a sketch of a properly oriented element.