The pump of a water distribution system is powered by a 15-kW electric motor whose efficiency is 90 percent. The water flow rate through the pump is 50 L/s. The diameters of the inlet and outlet pipes are the same, and the elevation difference across the pump is negligible. If the pressures at the inlet and outlet of the pump are measured to be 100 kPa and 300 kPa (absolute), respectively, determine
(a) The mechanical efficiency of the pump and
(b) The temperature rise of water as it flows through the pump due to the mechanical inefficiency.

Water 50 L/s motor Motor 15 kW 100 kPa pump