You want to compress air from $1 \mathrm{~atm}, 70^{\circ} \mathrm{F}$, to $2000 \mathrm{psig}$, using a staged compressor with interstage cooling to $70^{\circ} \mathrm{F}$. The maximum compression ratio per stage you can use is about 6 , and the compressor efficiency is $70 %$.

(a) How many stages should you use?

(b) Determine the corresponding interstage pressures.

(c) What power would be required to compress the air at a rate of $10^{5} \mathrm{scfm}$ ?

(d) Determine the temperature of the air leaving the last stage.

(e) How much heat (in Btu/h) must be removed by the interstage coolers?