Nitrogen flows at 1000 kg/h into a compressor at 1 bar and 300 K and leaves at 5 bar and 420 K, Cooling water flows through the compressor at the rate of 1400 kg/h, entering at 300 K and leaving at 320 K.

a) How much power is supplied to the compressor?

b) With the same cooling water flow rate and inlet temperature, calculate the minimum power required to attain the same change in state of nitrogen.

c) What is the efficiency of the compressor?