Solve the below:
Q: Helium gas is compressed from 14 psia and 70°F to 120 psia at a rate of 5 ft3/s. Determine the power input to the compressor, assuming the compression process to be
(a) Isentropic,
(b) Polytropic with n = 1.2,
(c) Isothermal, and
(d) Ideal two-stage polytropic with n = 1.2.