Question

Cylinder A = 30m high and 1m in diameter. It is full of seawater (density 1020kg/m3). Cylinder B is identical but is only 10% full of seawater.
At the side of cylinder A near the base, a pipe connects A and B via a one way valve only allowing seawater to flow INTO A.
How much power in watts would an air compressor positioned over the standing (10%) water in cylinder B require in order to force seawater through a 0.38m diameter pipe (and the one way valve) into cylinder A at a flow rate of one cubic metre per second?

Answer 1

solve Bernoulli's equation for the pressure at the surface of the water in B, using the parameter values at the water surfaces of A and B as input for the formula. The power is then just the pressure times the flow rate.