An electric motor converts electricity to rotating shaft work with an efficiency of 54%. The rotating shaft turns the impeller in the pump which, in turn, increases the pressure of the water (i=1000kg/m3) by 200 kPa. If the motor is consuming 3.5 kW of electricity, and water flow through the pump is 3.95 L/s, what is the mechanical efficiency with which the pump converts the rotation of the impeller into water pressure?