surface = γAdc where, γ = specific weight of water, A = area of the surface; d c = depth of center of gravity of the surface. Solution: Considering unit width of the gate, F 1 = (9.81 kN/m3)(2 m x 1 m) (h m) = 19.62h kN and, F 2 = (9.81 kN/m3)(h m x 1 m) (h/2 1