A C$.$I. flat, $300$ mm long and of $30mm50mm$ uniform section, is acted upon by the following forces uniformly distributed over the respective cross$-$section as shown in Figure $2$; $25$ kN in the direction of length $($tensile$)$; $350$ kN in the direction of the width $($compressive$)$; and $200$ kN in the direction of thickness $($tensile$).$ Determine the change in volume of the flat. Take $E=140G\frac{N}{m^2},$ and Poisson's ratio $=0\mathrm{.}25.$