---
title: "Two blocks of masses \\(m_1\\) and \\(m_2\\) rest on a frictionless horizontal surface and are connected by an ideal spring of spring constant \\(k\\). A constant horizontal external force of magnitude \\(F_0\\) is applied to the block of mass \\(m_1\\), pulling it to the right. At an instant when the spring is stretched by a displacement \\(x\\) from its unstretched length, what is the magnitude of the acceleration of the center of mass of the two-block system?"
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url: "https://nerd-notes.com/ubq/120546/"
date_modified: "2026-08-23T04:41:30+00:00"
---

# Two blocks of masses \(m_1\) and \(m_2\) rest on a frictionless horizontal surface and are connected by an ideal spring of spring constant \(k\). A constant horizontal external force of magnitude \(F_0\) is applied to the block of mass \(m_1\), pulling it to the right. At an instant when the spring is stretched by a displacement \(x\) from its unstretched length, what is the magnitude of the acceleration of the center of mass of the two-block system?

Two blocks of masses \(m_1\) and \(m_2\) rest on a frictionless horizontal surface and are connected by an ideal spring of spring constant \(k\). A constant horizontal external force of magnitude \(F_0\) is applied to the block of mass \(m_1\), pulling it to the right. At an instant when the spring is stretched by a displacement \(x\) from its unstretched length, what is the magnitude of the acceleration of the center of mass of the two-block system?

![A horizontal line represents a frictionless floor. Two rectangular blocks rest on the floor: a block labeled \(m_2\) on the left and a block labeled \(m_1\) on the right. A horizontal zigzag line representing a coiled spring labeled \(k\) connects the right face of block \(m_2\) to the left face of block \(m_1\). A single horizontal vector arrow labeled \(F_0\) starts at the right face of block \(m_1\) and points horizontally to the right. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787460090-MzEror.jpg)

- **A.** \(\dfrac{F_0 - kx}{m_1 + m_2}\)
- **B.** \(\dfrac{F_0}{m_1 + m_2}\)
- **C.** \(\dfrac{F_0}{m_1}\)
- **D.** \(\dfrac{F_0 - kx}{m_1}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120546/*