Question

A square gate is used to prevent seawater (density = 1027 kg/m^3) intrusion into a sewer main. The depth of water(density=1000 kg/m^3) in the sewer is 1.3 m, and the top and bottom of the gate 0.3m and 0.6m below the surface in the sewer . If the tide rises and falls such that the minimum and maximum heights of seawater are 2.6m and 3m . Calculate the force required at the base of gate to ensure there is no sea water flew into the sewer during the tide cycle.

Answer 1