Air flows into the jet engine shown in Fig. P$5\mathrm{.}2\mathrm{.}40$ at a rate of $9$ slugs$/$s and a speed of $300f\frac{t}{s}.$ Upon landing, the engine exhaust exits through the reverse thrust mechanism with a speed of $900f\frac{t}{s}$ in the direction indicated. Determine the reverse thrust applied by the engine to the airplane. Assume the inlet and exit pressures are atmospheric and that the mass flowrate of fuel is negligible compared to the air flowrate through the engine.

$V1=500f\frac{t}{s},V2=750f\frac{t}{s}$ and $V3=750f\frac{t}{s}$