---
title: "A block of mass \\(M\\) and a block of mass \\(2M\\) are connected by a light string and rest on a horizontal, frictionless surface. A constant horizontal force of magnitude \\(F\\) is applied to the block of mass \\(M\\) in a direction away from the other block, causing the system to accelerate. The block of mass \\(2M\\) is then replaced with a block of mass \\(5M\\), and the same force \\(F\\) is applied to the block of mass \\(M\\). What is the ratio of the system’s acceleration after the replacement to the system’s acceleration before the replacement?"
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url: "https://nerd-notes.com/ubq/109267/"
date_modified: "2026-03-21T18:52:26+00:00"
---

# A block of mass \(M\) and a block of mass \(2M\) are connected by a light string and rest on a horizontal, frictionless surface. A constant horizontal force of magnitude \(F\) is applied to the block of mass \(M\) in a direction away from the other block, causing the system to accelerate. The block of mass \(2M\) is then replaced with a block of mass \(5M\), and the same force \(F\) is applied to the block of mass \(M\). What is the ratio of the system’s acceleration after the replacement to the system’s acceleration before the replacement?

A block of mass \(M\) and a block of mass \(2M\) are connected by a light string and rest on a horizontal, frictionless surface. A constant horizontal force of magnitude \(F\) is applied to the block of mass \(M\) in a direction away from the other block, causing the system to accelerate. The block of mass \(2M\) is then replaced with a block of mass \(5M\), and the same force \(F\) is applied to the block of mass \(M\). What is the ratio of the system's acceleration after the replacement to the system's acceleration before the replacement?

![A horizontal diagram showing two rectangular blocks on a flat surface. On the left is a block labeled 2M, and on the right is a block labeled M. A thin line represents a string connecting the centers of the two blocks. A horizontal arrow labeled F points to the right, originating from the right side of block M.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1774119145-ZxvfBi.jpg)

- **A.** \(1/5\)
- **B.** \(2/5\)
- **C.** \(1/2\)
- **D.** \(5/2\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/109267/*