Aturbojet is flying with a velocity of 900 ft/s at an altitude of 20,000 ft, where the ambient conditions are 7 psia and 10°f. the pressure ratio across the compressor is 13, and the temperature at the turbine inlet is 2250 r. assume ideal operation for all components and account for the variation of specific heats with temperature. determine (a) the pressure at the turbine exit, (b) the velocity of the exhaust gases, and (c) the propulsive efficiency.