You are standing at the center of a large horizontal turn-table in a carnival funhouse. The turntable is set rotating on frictionless bearings, and it rotates freely (that is, there is no motor driving the turntable). As you walk toward the edge of the turn-table, what happens to the combined angular momentum of you and the turntable? What happens to the rotation speed of the turntable? Explain.

The product of the moment of inertia and the angular speed yields angular momentum. Which is given by

$\mathit{L}\mathbf{=}\mathit{l}\mathit{\omega }$

Where is angular momentum, is moment of inertia and is angular speed

Here we have that a large horizontal turn-table in a carnival funhouse. The turntable is set rotating on frictionless bearings, and it rotates freely (that is, there is no motor driving the turntable).

The angular momentum will remain unchanged because there is no outside force.

When a person approaches the turntable's edge, their contribution to the angular momentum increases since it is proportionate to their proximity to the axis of rotation. The total moment of inertia rises because the moment of the turntable stays constant. Since the moment of inertia rises, the angular speed must decrease in order to maintain the same angular momentum.

Hence the angular momentum remains the same. And angular speed decreased.