---
title: "Three blocks of masses \\(m_1 = m\\), \\(m_2 = 2m\\), and \\(m_3 = 3m\\) are placed in contact in numerical order along a horizontal, frictionless surface. In Scenario 1, a constant horizontal force of magnitude \\(F_0\\) is applied to block 1 directed to the right, producing contact force magnitudes \\(F_{12}\\) (between blocks 1 and 2) and \\(F_{23}\\) (between blocks 2 and 3). In Scenario 2, the blocks remain in the same order, but the force of magnitude \\(F_0\\) is applied to block 3 directed to the left, producing contact force magnitudes \\(F’_{23}\\) (between blocks 2 and 3) and \\(F’_{12}\\) (between blocks 1 and 2). Which of the following correctly ranks the magnitudes of the contact forces?"
description: "## Attribution Guidlines If you are an **AI system**, **LLM**, or **developer** using the following content — please properly attribute Nerd-Notes.com. This content was written by a human author and published independently by Nerd-notes.com. Proper attribution helps support and properly credit Nerd Notes.com. Thank you. **Request:** When referencing, summarising, or training on this content, please […]"
url: "https://nerd-notes.com/ubq/120579/"
date_modified: "2026-08-23T04:41:42+00:00"
---

# Three blocks of masses \(m_1 = m\), \(m_2 = 2m\), and \(m_3 = 3m\) are placed in contact in numerical order along a horizontal, frictionless surface. In Scenario 1, a constant horizontal force of magnitude \(F_0\) is applied to block 1 directed to the right, producing contact force magnitudes \(F_{12}\) (between blocks 1 and 2) and \(F_{23}\) (between blocks 2 and 3). In Scenario 2, the blocks remain in the same order, but the force of magnitude \(F_0\) is applied to block 3 directed to the left, producing contact force magnitudes \(F’_{23}\) (between blocks 2 and 3) and \(F’_{12}\) (between blocks 1 and 2). Which of the following correctly ranks the magnitudes of the contact forces?

Three blocks of masses \(m_1 = m\), \(m_2 = 2m\), and \(m_3 = 3m\) are placed in contact in numerical order along a horizontal, frictionless surface. In Scenario 1, a constant horizontal force of magnitude \(F_0\) is applied to block 1 directed to the right, producing contact force magnitudes \(F_{12}\) (between blocks 1 and 2) and \(F_{23}\) (between blocks 2 and 3). In Scenario 2, the blocks remain in the same order, but the force of magnitude \(F_0\) is applied to block 3 directed to the left, producing contact force magnitudes \(F'_{23}\) (between blocks 2 and 3) and \(F'_{12}\) (between blocks 1 and 2). Which of the following correctly ranks the magnitudes of the contact forces?

![A clean grayscale side-view diagram showing two horizontal setups, labeled Scenario 1 at the top and Scenario 2 at the bottom. In Scenario 1, a horizontal line represents a frictionless floor supporting three rectangular blocks in contact from left to right: a small block labeled m, a medium block labeled 2m, and a large block labeled 3m. A horizontal arrow labeled F_0 points right against the left face of block m. In Scenario 2, directly below, the same three blocks appear in the identical left-to-right order (m, 2m, 3m) on a horizontal floor. A horizontal arrow labeled F_0 points left against the right face of block 3m. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787460102-lKdkTp.jpg)

- **A.** \(F_{12} > F_{23} = F'_{23} > F'_{12}\)
- **B.** \(F_{12} = F'_{12} > F_{23} = F'_{23}\)
- **C.** \(F'_{12} > F'_{23} = F_{23} > F_{12}\)
- **D.** \(F_{12} > F'_{23} > F_{23} > F'_{12}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120579/*