Problem 5/188 5/189 The rectangular gate shown in section is 10 ft long (perpendicular to the paper) and is hinged about its upper edge B. The gate divides a channel leading to a fresh-water lake on the left and a salt-water tidal basin on the right. Calculate the torque M on the shaft of the gate at B required to prevent the gate from opening when the salt-water level drops to h = 3 ft. Ans. M 11.22(104) lb-ft = B M 3' h 12' Fresh water Salt water A Problem 5/189 5