Final answer:
A Ferris wheel starting to turn experiences forces including gravitational force, normal force, and tension, which can affect its angular velocity and angular momentum. The wheel's angular momentum changes in response to external torques caused by these forces.
Step-by-step explanation:
When a Ferris wheel, with cars at 4 o'clock, 1 o'clock, 9 o'clock, and 6 o'clock, starts to turn, there are several forces acting on it. These forces include gravitational force, normal force, tension in the support cables, and possibly friction and air resistance. The gravitational force acts downwards, causing the wheel to rotate. The normal force acts perpendicular to the contact surface and helps support the wheel. Tension in the cables provides a centripetal force, necessary for circular motion. Friction, if present, may oppose the motion and affect the angular velocity, while air resistance could slow down the wheel.
The angular velocity of the wheel can change due to external torques caused by these forces, depending on how they are applied. The wheel's angular momentum is a product of its moment of inertia and its angular velocity. If external torques are applied (like those due to asymmetric loading), there will be changes in the angular velocity and, consequently, the angular momentum of the Ferris wheel.