1. Helium flows at 75 psia, 900 R, 330 ft/s into a convergent-divergent nozzle. Find the throat pressure and temperature for reversible flow and M = 1 at the throat.
2. The products of combustion enter a nozzle of a jet engine at a total pressure of 18 lbf/in.2 and a total temperature of 1200 F. The atmospheric pressure is 6.75 lbf/in.2. The nozzle is convergent, and the mass flow rate is 50 lbm/s. Assume the flow is air and adiabatic. Determine the exit area of the nozzle.