An air standard Diesel cycle has a compression ratio of 17.9. Air is at 85oF and 15.8 psia at the beginning of the compression process and at 3100oR at the end of the heat addition process. Accounting for the variation of specific heats with temperature, determine
(a) The cutoff ratio,
(b) The heat rejection per unit mass and
(c) The thermal efficiency. Use the IG model for air.