8.40 Two water tanks are connected by a horizontal pipeline. The first tank has a square-edged outlet 3 m below the surface that is connected to a 50-mm-diameter PVC pipe. At 15 m from the tank the pipe is connected to a 100-mm-diameter pipe which runs 30 m to the outlet that is 0.6m below the surface of the second tank.

The water temperature is 20 C. Determine the flow rate through the pipe line.