Nitrogen, traveling at 12 m/s with a pressure of 14 bar abs. at a temperature of 800 K, enters a device with an area of 0.05 m2 . No work or heat transfer takes place. The temperature at the exit, where the area is 0.15 m2 , has dropped to 590 K. What are (a) the velocity and (b) pressure at the outlet section?

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?