The two$-$segment statically indeterminate bar in the following figure has a constant crosssectional area $A=0\mathrm{.}8i{n}^2.$ It is made entirely of material that has elastic, perfectly plastic behaviour with $y=36$ksi and $E=30{10}^3$ksi. If $P=45$ kip is applied to the bar and then removed

a$)$ Determine the residual stress in each segment.

b$)$ Find the permanent deformation at point B$.$

c$)$ Determine the smallest load $P$ needed to cause segment CB to yield.

$5\mathrm{.}67$ ksi

$7\mathrm{.}5$ ksi

$10$ ksi

$36$ ksi

$65\mathrm{.}15$ ksi

$0\mathrm{.}104242$ in

$80$ kip