Refrigerant 134a enters a diffuser, as saturated vapor at 800 kPa with a constant velocity of 120 m/s, and leaves at 900 kPa and 40C. The refrigerant gains heat at a rate of 2 kJ/s as it passes through the diffuser. . If the outlet area is 80% greater than the inlet area, determine a) the outlet velocity and b) the mass flow of refrigerant mass.