A gate AB is hinged at A. When closed, it is inclined at an angle of 60 °C. It is a rectangular and has a length of 0.6m and a width of 1m. There is water on both sides of the gate. Furthermore, compressed air exerts a pressure of 20 kPa gage on the surface of the water on the left side of the gate, while the water on the right side is exposed to atmospheric pressure. (a) What is the moment about the hinge A exerted by the water on the gate? (b) A 1.2m layer of oil, having a specific gravity of 0.8, is added to the top of the water on the right of the gate. What is the total moment about A from the water on the gate?