An engineer has proposed that a simple ideal Rankine cycle that uses Refrigerant 134a be used to produce work with heat from a low temperature thermal reservoir. The boiler operates at 1.6 MPa, the condenser at 0.4 MPa, and the turbine inlet at 80 C. Determine the R134a mass flow rate needed for this cycle to produce 750 kW of power and the thermal efficiency of the cycle.