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The rotor of a turbojet engine of an aircraft has a mass 180 kg and polar moment of inertia 10 kg·m² about the rotor axis. The rotor rotates at a constant speed of 1100 rad/s in the clockwise direction when viewed from the front of the aircraft. The aircraft while flying at a speed of 800 km per hour takes a turn with a radius of 1.5 km to the left. The gyroscopic moment exerted by the rotor on the aircraft structure and the direction of motion of the nose when the aircraft turns, are

1. 1629.6 N·m and the nose goes up
2. 1629.6 N·m and the nose goes down
3. 162.9 N·m and the nose goes up
4. 162.9 N·m and the nose goes down

Correct answer: 1629.6 N·m and the nose goes down

Solution

The gyroscopic moment is calculated using the formula for gyroscopic precession, which results in a value of 1629.6 N·m. When the aircraft turns left, the gyroscopic effect causes the nose to pitch down due to the direction of the angular momentum vector and the applied force from the turn.

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