Nitrogen initially occupying 3.5 ft3 at 87 psia, 480°F undergoes in internally reversible expansion during which PV1.2 = constant to a final state where the temperature is 100°F. Assuming the ideal gas model, determine
(a) The pressure at the final state, in psia
(b) The work and heat transfer, each in Btu.
(c) The entropy change, in Btu/R.