One side of a mercury manometer is connected to the top of frictionless piston-cylinder storage tank containing 1500 liters of oil, the other side is open to the atmosphere. The difference in the height of the column of mercury in the manometer is 90 cm. At this time, the tank is full of oil and the atmospheric pressure is 98 kPa. The density of oil is 780 kg/m^3 and that of the mercury is 13,600 kg/m^3. The diameter of the tank is 100 cm. Draw schematic diagram and determine:
a. the absolute pressure of the oil at the top of the tank in kPa,
b. the mass of piston on top of the tank,
c. the absolute pressure of the oil in the tank in kg, and
e. the weight of the oil in tank in N if the local gravitational acceleration is 9.60 m/s^2.