An ideal gas is treated through a two$-$step process. First, the volume of the gas is reduced from $0\mathrm{.}500m^3$ to $0\mathrm{.}325m^3$ at a constant pressure of $1\mathrm{.}00{10}^{5}Pa.$ In the second step, the pressure is increased from $1\mathrm{.}00{10}^{5}Pa$ to $4\mathrm{.}25{10}^{5}Pa$ at a constant volume of $0\mathrm{.}325m^3.$

$($a$)$ sketch the PV diagram for the process

$($b$)$ calculate the work done by the gas from the PV diagram.