air at 1080r and 116 psi enters a single-inlet, single-exit control volume at a velocity of 131 ft/s. the inlet area is 3.1 in2. the fluid exits at 720⁰r and 29 psi with a velocity of 1148 ft/s. the air behaves as an ideal gas. for steady state operation, find (a) the mass flow rate and (b) the exit flow area.