4. A centrifugal pump (its characteristic curve is shown below (240 mm impeller diameter)) is used to transfer 20 °C water from the well to a storage tank. If the flow through the 75-mm-diameter pipe is to be 0.02 m3/s, determine the height when the pump should turn off to avoid cavitation occurrence. Take the friction factor for the pipe to be f = 0.02 and neglect minor losses. (Note: take the datum as shown in the figure)