Question $1[20$ Marks$]$

A cast$-$iron pipe with an outside diameter of $500mm$ and $30-$mm thickness is used as a short column $2,5m$ long. The inside of the column is filled with concrete. If the column is to carry a compressive load of $1200kN,$ calculate the stresses induced in the cast iron and concrete as well as the amount by which the column shortens.

$E_{\text{c}\text{o}\text{n}\text{c}\text{r}\text{e}\text{l}\text{e}}=14$GPa and $E_{\text{c}\text{a}\text{s}\text{t}\text{i}\text{o}\text{n}}=140$GPa