---
title: "A small block of mass \\(m\\) is placed on a horizontal disk at a distance \\(r\\) from the center. The disk rotates about its center with a constant angular speed \\(\\omega\\). The block remains at rest relative to the disk. A second block of mass \\(2m\\) is made of the same material as the first block and is placed at the same distance \\(r\\) from the center. The disk again rotates at the same constant angular speed \\(\\omega\\). Which of the following correctly identifies the force providing the centripetal acceleration and predicts whether the second block will slip?"
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url: "https://nerd-notes.com/ubq/110295/"
date_modified: "2026-04-01T05:54:39+00:00"
---

# A small block of mass \(m\) is placed on a horizontal disk at a distance \(r\) from the center. The disk rotates about its center with a constant angular speed \(\omega\). The block remains at rest relative to the disk. A second block of mass \(2m\) is made of the same material as the first block and is placed at the same distance \(r\) from the center. The disk again rotates at the same constant angular speed \(\omega\). Which of the following correctly identifies the force providing the centripetal acceleration and predicts whether the second block will slip?

A small block of mass \(m\) is placed on a horizontal disk at a distance \(r\) from the center. The disk rotates about its center with a constant angular speed \(\omega\). The block remains at rest relative to the disk. A second block of mass \(2m\) is made of the same material as the first block and is placed at the same distance \(r\) from the center. The disk again rotates at the same constant angular speed \(\omega\). Which of the following correctly identifies the force providing the centripetal acceleration and predicts whether the second block will slip?

![A side-view diagram shows a flat horizontal disk. A vertical dashed line passes through the center of the disk to indicate the axis of rotation. A small square block is positioned on the top surface of the disk at a horizontal distance r from the axis. A curved arrow around the axis indicates the disk is rotating with an angular speed omega.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1775022878-TKwck1.jpg)

- **A.** Static friction provides the centripetal acceleration. The second block will not slip because both the required centripetal force and the maximum possible static friction force increase by the same factor.
- **B.** Static friction provides the centripetal acceleration. The second block will slip because the required centripetal force is proportional to the mass, but the coefficient of static friction is a constant property of the surfaces.
- **C.** The normal force provides the centripetal acceleration. The second block will not slip because the normal force acts toward the center of the disk and increases proportionally with the mass of the block.
- **D.** The normal force provides the centripetal acceleration. The second block will slip because the normal force acts vertically, and thus the required centripetal force cannot be provided as the mass increases.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/110295/*