A turbojet engine is shown in cruise condition. The flight condition is known to be: M, = 2.0, Po = 20 kPa, To = -35C with y = 1.4 and R = 287 J/kg.K. The air mass flow rate into the engine is known to be mo = 110 kg/s. The fuel flow rate to the combustor is m, = 4.2 kg/s with heating value QR = 42,800 kJ/kg. If the nozzle is perfectly expanded and the exhaust velocity is V, = 1,200 m/s, calculate: (a) Ram drag, D, in kN and lbf (b) Gross thrust, Fg, in kN and lbf (c) Net un-installed thrust in KN (d) TSFC in mg/s/N and lbm/hr/lbf (e) Engine thermal efficiency, th (f) Propulsive efficiency, np 0 mo FIGURE P 3.21 ms