1. A steady-flow device receives R-410a at 40?C, 800 kPa and it exits at 40?C, 100 kPa. Assume a reversible isothermal process. Find the change in specific exergy.
2. Consider the springtime melting of ice in the mountains, which provides cold water running in a river at 2?C while the air temperature is 20?C. What is the exergy of the water relative to the ambient temperature?
3. Nitrogen flows in a pipe with a velocity of 300 m/s at 500 kPa, 300?C. What is its exergy with respect to an ambient at 100 kPa, 20?C?