TUTORIAL EXERCISE:STMCI$021$A square steel rod $15$ mm x $15$ mm in cross secion with alength of $795$ mm is positioned in a concenlric manner wilhina copper tube. The copper tube has an intermal diameter of$40$ mm and a thickness of $5$ mm$.$ The rod is $0\mathrm{.}5$ mm longerthan the tube. An axial compressive load is exerted on therod through rigid plates located at its ends. Determine theload at whlch the rod and tube exhibil equal lengths,considering the given Young's modulus values of steel $(210000$ MPa$)$ and copper $(110000$ N$/$mm$^2).$