---
title: "A small rock sits at the bottom of a cup filled with water. The upward force exerted by the water on the rock is \\( F_0 \\). The water is then poured out and replaced by an oil that is \\( \\frac{3}{4} \\) as dense as water, and the rock again sits at the bottom of the cup, completely under the oil. Which of the following expressions correctly represents the magnitude of the upward force exerted by the oil on the rock?"
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/81521/"
date_modified: "2025-03-13T04:20:17+00:00"
---

# A small rock sits at the bottom of a cup filled with water. The upward force exerted by the water on the rock is \( F_0 \). The water is then poured out and replaced by an oil that is \( \frac{3}{4} \) as dense as water, and the rock again sits at the bottom of the cup, completely under the oil. Which of the following expressions correctly represents the magnitude of the upward force exerted by the oil on the rock?

A small rock sits at the bottom of a cup filled with water. The upward force exerted by the water on the rock is \( F_0 \). The water is then poured out and replaced by an oil that is \( \frac{3}{4} \) as dense as water, and the rock again sits at the bottom of the cup, completely under the oil. Which of the following expressions correctly represents the magnitude of the upward force exerted by the oil on the rock?

- **A.** \[ \frac{3}{4} F_0 \]
- **B.** \[ F_0 \]
- **C.** \[ \frac{4}{3} F_0 \]
- **D.** The answer cannot be determined without knowing the rock’s volume.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/81521/*