---
title: "The diagram above shows a top view of a child of mass M on a circular platform of mass 2M that is rotating counterclockwise. Assume the platform rotates without friction. Which of the following describes an action by the child that will increase the angular speed of the platform-child system and gives the correct reason why?"
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url: "https://nerd-notes.com/ubq/29479/"
date_modified: "2025-03-03T08:17:26+00:00"
---

# The diagram above shows a top view of a child of mass M on a circular platform of mass 2M that is rotating counterclockwise. Assume the platform rotates without friction. Which of the following describes an action by the child that will increase the angular speed of the platform-child system and gives the correct reason why?

The diagram above shows a top view of a child of mass \(M\) on a circular platform of mass \(2M\) that is rotating counterclockwise. Assume the platform rotates without friction. Which of the following describes an action by the child that will increase the **angular speed** of the platform-child system and gives the correct reason why?

![Diagram](https://nerd-notes.com/wp-content/uploads/2024/03/Screenshot-2024-03-28-at-4.13.49-PM-300x293.png)

- **A.** The child moves toward the center of the platform, increasing the total angular momentum of the system
- **B.** The child moves toward the center of the platform, decreasing the rotational inertia of the system.
- **C.** The child moves away from the center of the platform, increasing the total angular momentum of the system.
- **D.** The child moves away from the center of the platform, decreasing the rotational inertia of the system.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/29479/*