$2$

$13$

For a $7m$ tall column $($pin ended in a braced structure$)$ that supports an un$-$factored dead load of $350kN$ and un$-$factored live load of $200kN.$ Column's dimensions: $500mm**500mm,f^{\text{'}}C=24$ MPa,$fy=420$MPa. The bending moment diagram for the column is shown below.

Consider the following;

$Bd=0\mathrm{.}5676$

Find only, the critical moment $(M_c)$ and load $(P_u)$ to be used in the design of this column. Don't use the sheets of interaction diagrams