Methane is compressed in two-stage, double-acting compressor which is electrically driven at 165 rpm. The low pressure cylinder (30.5 x 35.5 cm) receives 6.86 cu m per minute of air at 96.53 kPa, 43.30C, and the high pressure cylinder (20.3 x 35.5 cm) discharges the methane at 717.06 kPa. The isothermal overall efficiency is 74%. Find n and the kW output of the motor. Ans: 80.02%, 90.86%