A tank with a square base of area $1.0{\mathrm{m}}^2$ is divided by a vertical partition in the middle. The bottom of the partition has a small hinzed door of area  $20{\mathrm{cm}}^2.$ The tank is filled with water in one compartment and an acid of relative density 1.7 in the other, both to a height of 4 m. The force acting on the door is $\left(\mathrm{g}=10{\mathrm{ms}}^{-2}\right)$