A fuel oil tank is an upright cylinder, buried so that its circular top 12 feet beneath ground level. The tank has a radius of 6 feet and is 18 feet high, although the current oil level is only 13 feet deep. Calculate the work required to pump all of the oil to the surface. Oil weighs 50 lb/ft^3.

Answer 1

the center of mass of the oil is 12+5+6.5 = 23.5 feet below the surface

The weight of oil is 50*π*6^2*13 = 23400π lbs

work = force*distance = 23400π*23.5 ft-lbs