d$)$ An open rectangular storage tank with vertical walls is first filled with water to a height of $1\mathrm{.}5$ m from the bottom. This is then covered by a layer of oil. The depth of the oil column is such that its weight is $35\%$ of the weight of the water column. Calculate the total pressure force acting on a $2$ m wide vertical wall of the tank due to the columns of oil and water. The ambient temperature and pressure are $15C$ and $1$ bar respectively. The densities of water and oil are $1000k\frac{g}{m^3}$ and $700k\frac{g}{m^3}$ respectively.

$[6$ marks$]$