The hydrostatic force is F, = yh A = y (0.5)1 = 4905 N The center of pressure is at 2/3 the distance from the water surface since the gate extends from the free surface. Hence y, = 2/3 The force F is obtained from the moment equilibrium equation when applied at the hinge, i.e. [M = 4905(2/3) - F(1) = 0