A tank with a square base of area 1.0 m2 is divided by a vertical partition in the middle

A tank with a square base of area 1.0 m2 is divided by a vertical partition in the middle. The bottom of die partition has small-hinged door of area 20 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 4.0 m. Compute the force necessary to keep one door closed