1. The compressor of a refrigerator compresses saturated R-134a vapor at 10ºC to 800 kPa. How much work, in kJ/kg, does this process require when the process is isentropic?
2. Helium gas enters a nozzle whose isentropic efficiency is 94 percent with a low velocity, and it exits at 14 psia, 180°F, and 1000 ft/s. Determine the pressure and temperature at the nozzle inlet.