Acommercial aircraft requires 18,000 hp to cruise with 900 km/h at 10,000 m altitude. determine the required power for the following cases: (a) the aircraft cruises at the sea level with the same speed. comment on your answer (b) the aircraft cruises with 450 km/h at the same altitude.

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?