AAI ATC Junior Executive 25 Mar 2021 Shift 2 Paper

A tank with a square base of area 1.0 m² is divided by a vertical partition in the middle. The bottom of the partition has a small-hinged door of area 10 cm2. The tank is filled with water in one compartment, and an acid (of relative density 1.7) in the other, both to a height 3.0 m. Calculate the force necessary to keep the door close?