An aircraft cooling system bleeds air from the engine compressor at 300 kPa and 200 C at the rate 0.09 kg/s. The air is cooled in a heat exchanger and then expanded through a turbine before being supplied to the aircraft cockpit at 60 kPa and 4C. Neglect friction and neglect changes in kinetic energy to find (a) the heat transfer in the heat exchanger (kW) (b) the power output of the turbine (kW). Explain thought process and tables used.