---
title: "Three blocks of masses \\(m_1\\), \\(m_2\\), and \\(m_3\\) are stacked vertically on a rough horizontal floor, with block 2 situated between block 1 on top and block 3 on the bottom. A constant horizontal force of magnitude \\(F\\) is applied to block 2 to the right, causing the entire three-block system to accelerate together to the right without slipping between any of the blocks. Which of the following diagrams correctly represents all the individual forces acting on block 2, along with their relative magnitudes and directions?"
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/124187/"
date_modified: "2026-09-28T13:31:03+00:00"
---

# Three blocks of masses \(m_1\), \(m_2\), and \(m_3\) are stacked vertically on a rough horizontal floor, with block 2 situated between block 1 on top and block 3 on the bottom. A constant horizontal force of magnitude \(F\) is applied to block 2 to the right, causing the entire three-block system to accelerate together to the right without slipping between any of the blocks. Which of the following diagrams correctly represents all the individual forces acting on block 2, along with their relative magnitudes and directions?

Three blocks of masses \(m_1\), \(m_2\), and \(m_3\) are stacked vertically on a rough horizontal floor, with block 2 situated between block 1 on top and block 3 on the bottom. A constant horizontal force of magnitude \(F\) is applied to block 2 to the right, causing the entire three-block system to accelerate together to the right without slipping between any of the blocks. Which of the following diagrams correctly represents all the individual forces acting on block 2, along with their relative magnitudes and directions?

![A schematic diagram showing three rectangular blocks stacked vertically on a horizontal line representing a rough floor. The bottom block is labeled \(m_3\) and rests on the floor. Directly on top of block \(m_3\) is a middle block labeled \(m_2\). Directly on top of block \(m_2\) is a top block labeled \(m_1\). All three blocks are identical in width and height. A horizontal arrow pointing to the right starts at the right vertical edge of block \(m_2\) and is labeled \(F\). A separate horizontal arrow pointing to the right is located above the top block and is labeled \(a\). The floor is indicated by a solid horizontal line with short hatching slanting downward to the left below it. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1790602262-BrvcBs.jpg)

- **A.** Upward normal force \(N_{32}\); downward normal force \(N_{12}\) and downward gravity \(F_{g,2}\) with \(N_{32} = N_{12} + F_{g,2}\); rightward forces \(F\) and \(f_{12}\); leftward friction force \(f_{32}\), with \(F + f_{12} > f_{32}\).
- **B.** Upward normal force \(N_{32}\); downward normal force \(N_{12}\) and downward gravity \(F_{g,2}\) with \(N_{32} = N_{12} + F_{g,2}\); rightward force \(F\); leftward friction forces \(f_{12}\) and \(f_{32}\), with \(F > f_{12} + f_{32}\).
- **C.** Upward normal force \(N_{32}\) equal in magnitude to downward gravity \(F_{g,2}\) only; rightward force \(F\); leftward friction forces \(f_{12}\) and \(f_{32}\), with \(F > f_{12} + f_{32}\).
- **D.** Upward normal force \(N_{32}\); downward normal force \(N_{12}\) and downward gravity \(F_{g,2}\) with \(N_{32} = N_{12} + F_{g,2}\); rightward force \(F\); leftward friction forces \(f_{12}\) and \(f_{32}\), with \(F = f_{12} + f_{32}\).

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/124187/*