Refrigerant-134a enters an insulated diffuser as a saturated vapor at 80°f with a velocity of 800 ft/s. the inlet area is 1.5 in2. at the exit, the pressure is 400 lbf/in2 and the velocity is negligible. the diffuser operates at steady state and potential energy effects can be neglected. determine the mass flow rate, in lb/s, and the exit temperature, in °f