An open 6 m-diameter tank contains water at 20oC and an oil (SG = 0.78) to a total depth of 9m.A mercury U-tube manometer is connected, at one end, to a pressure tapping on the tank wall at1.2 m above the base. The other end of the U-tube is open to the atmosphere. Initially, when the tank was empty, the mercury levels were the same and measured 50 cm below the pressure tapping point. If the difference in mercury levels now is 60 cm, what are the depths and volumes of the two liquids in the tank ? Hint: (i) draw a schematic diagram for the system first; (ii) assume the pressure tapping point is below the oil/water interface.(Answer :Oil: 2.0 m; 56.5 m3). show the steps.