Final answer:
Gyroscopes used in guidance systems maintain a constant angular momentum direction due to inertia, and the precession caused by any applied torque preserves the original angular momentum direction.
Step-by-step explanation:
The reason a gyroscope used in guidance systems can maintain a constant angular momentum direction, even when subjected to large forces and accelerations, is due to its inertia. According to the conservation of angular momentum, unless acted upon by an external torque, a gyroscope's angular momentum will not change. The inherent property of a spinning gyroscope is to resist changes to its orientation due to its angular momentum. This phenomenon is known as precession, where any applied torque causes the gyroscope to rotate, or precess, around an axis perpendicular to the torque instead of in the direction of the applied force, thus preserving the direction of its original angular momentum.
The correct answer from the choices provided that describes this behavior is (b) Inertia of the gyroscope. When the vehicle that contains the gyroscope moves or changes orientation, the spinning gyro essentially 'ignores' these changes and maintains its initial orientation due to its rotational inertia, thus ensuring a constant direction of angular momentum which is critical for accurate guidance.