A pump in a food processing facility moves R22 refrigerant from a pipe with an inlet diameter of 8 cm into a pipe with an outlet diameter of 15 cm at a rate of 0.1 m3/s. Electric power is supplied to the pump at a rate of 105 kW. The density of the refrigerant is rho = 860 kg/m3. The pressure rise across the pump is Delta P = 650 kPa and the motor efficiency is eta = 85%. Determine the mechanical efficiency of the pump.