Meriam, Kraige & Bolton — Kinetics of Systems of Particles: Problem 4_49

4/49 The military jet aircraft has a gross weight of 24,000 lb and is poised for takeoff with brakes set while the engine is revved up to maximum power. At this condition, air with a specific weight of \(0.0753 \text{ lb/ft}^3\) is sucked into the intake ducts at the rate of \(106 \text{ lb/sec}\) with a static pressure of \(-0.30 \text{ lb/in.}^2\) (gage) across the duct entrance. The total cross-sectional area of both intake ducts (one on each side) is \(1800 \text{ in.}^2\). The air–fuel ratio is 18, and the exhaust velocity \(u\) is \(3100 \text{ ft/sec}\) with zero back pressure (gage) across the exhaust nozzle. Compute the initial acceleration \(a\) of the aircraft upon release of the brakes.