Air is compressed in a reversible steady-flow system from 15 psia and 100?F to an exit pressure of 100 psia. The compression process is polytropic, with a polytropic exponent of n = 1.250 the air may be assigned to behave as an ideal gas with constant specific heats. Determine: (i) the change in entropy, (ii) the work of compression per unit mass and (iii) the heat transferred per unit mass.