Question

Suppose the platform with the kid in the previous problem is rotating in anticlockwise direction at an angular speed ω. The kid starts walking along the rim with a speed v relative to the platform also in the anticlockwise direction. Find the new angular speed of the platform.

Answer 1

When a child walks along the rim of a rotating platform in the anticlockwise direction, the angular momentum of the system increases, resulting in an increase in the platform's new angular speed.

Step-by-step explanation:

When a child walks along the rim of a rotating platform in the anticlockwise direction, the angular momentum of the system increases. As a result, the platform's new angular speed will also increase.

Let's consider the initial and final angular momentums:

Initial angular momentum = (Mass of platform * Initial angular velocity) + (Mass of child * Initial angular velocity)

Final angular momentum = (Mass of platform * Final angular velocity) + (Mass of child * Final angular velocity)

Since the angular momentum is conserved, the initial angular momentum is equal to the final angular momentum:

(Mass of platform * Initial angular velocity) + (Mass of child * Initial angular velocity) = (Mass of platform * Final angular velocity) + (Mass of child * Final angular velocity)

You can solve this equation to find the new angular velocity of the platform.