Question #$6$

An aluminum rod is made in the form of a hollow square tube. $2\mathrm{.}5$ in outside, with a wall thickness of $0\mathrm{.}150in.$ Its length is $16\mathrm{.}0in.$

a$)$ What axial compressive force would cause the tube to shorten by $0\mathrm{.}005$ in$?$

b$)$ Compute the resulting compressive stress in the aluminum.