A 3-m-high, 6-m-wide rectangular gate is hinged at the top edge at A and is restrained by a fixed ridge at B. Determine the hydrostatic forced exerted on the gate by the 5-m-high water and the location of the pressure center

The flow of water from a container is controlled by a 5-ft-wide L-shaped gate hinged at point A, as shown in the figure. If it is desired that the gate open when the height of the water is 10 ft, determine the weight W of the counterweight to achieve this. Take d= 5 ft and H = 16 ft. Give your answer in lb and without decimals.