The minimum mass of the gate in kg per unit width , required to keep it closed is

Question

A hinged gate of length 5 m, inclined at 30⁰ with the horizontal and with water mass on its left, is shown in the figure below. Density of water is 1000 kg/m³. The minimum mass of the gate in kg per unit width (perpendicular to the plane of paper), required to keep it closed is

(a) 5000           (b) 6600           (c) 7546                       (d) 9623