---
title: "Engineers are testing two different crash-safety systems by observing cars brought to rest from an initial speed. In Test 1, a car of mass \\(M\\) traveling at speed \\(v\\) is brought to rest in a time interval \\(\\Delta t\\). In Test 2, a different car of mass \\(2M\\) traveling at speed \\(3v\\) is brought to rest in a time interval \\(4\\Delta t\\). If the average net force exerted on the car during Test 1 is \\(F_1\\) and the average net force exerted on the car during Test 2 is \\(F_2\\), what is the ratio \\(F_2/F_1\\)?"
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url: "https://nerd-notes.com/ubq/109211/"
date_modified: "2026-03-21T11:09:48+00:00"
---

# Engineers are testing two different crash-safety systems by observing cars brought to rest from an initial speed. In Test 1, a car of mass \(M\) traveling at speed \(v\) is brought to rest in a time interval \(\Delta t\). In Test 2, a different car of mass \(2M\) traveling at speed \(3v\) is brought to rest in a time interval \(4\Delta t\). If the average net force exerted on the car during Test 1 is \(F_1\) and the average net force exerted on the car during Test 2 is \(F_2\), what is the ratio \(F_2/F_1\)?

Engineers are testing two different crash-safety systems by observing cars brought to rest from an initial speed. In Test 1, a car of mass \(M\) traveling at speed \(v\) is brought to rest in a time interval \(\Delta t\). In Test 2, a different car of mass \(2M\) traveling at speed \(3v\) is brought to rest in a time interval \(4\Delta t\). If the average net force exerted on the car during Test 1 is \(F_1\) and the average net force exerted on the car during Test 2 is \(F_2\), what is the ratio \(F_2/F_1\)?

![Two horizontal paths are shown. In the top path, a small rectangular block representing a car with label M is moving to the right with a velocity vector v toward a vertical barrier. In the bottom path, a larger rectangular block with label 2M is moving to the right with a longer velocity vector labeled 3v toward the same barrier.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1774091388-V4gg7W.jpg)

- **A.** \(1/2\)
- **B.** \(3/4\)
- **C.** \(3/2\)
- **D.** \(6\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/109211/*