Air enters the compressor of an ideal Brayton refrigeration cycle at 100 kPa, 270 K. The compressor pressure ratio is 3, and the temperature at the turbine inlet is 315 K. The compressor and turbine have isentropic efficiencies of 82% and 85%, respectively. Determine: a. The heat into the cycle, in kJ/kg. b. net work input, per unit mass of air flow, in kJ/kg. c. The coefficient of performance