---
title: "A rock is whirled on the end of a string in a horizontal circle of radius \\(R\\) with a constant period \\(T\\). If the radius of the circle is reduced to \\(R/3\\), while the period remains \\(T\\), what happens to the centripetal acceleration (\\(a_c\\)) of the rock?"
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url: "https://nerd-notes.com/ubq/20990/"
date_modified: "2025-04-09T02:08:06+00:00"
---

# A rock is whirled on the end of a string in a horizontal circle of radius \(R\) with a constant period \(T\). If the radius of the circle is reduced to \(R/3\), while the period remains \(T\), what happens to the centripetal acceleration (\(a_c\)) of the rock?

A rock is whirled on the end of a string in a horizontal circle of radius \(R\) with a constant period \(T\). If the radius of the circle is reduced to \(R/3\), while the period remains \(T\), what happens to the centripetal acceleration (\(a_c\)) of the rock?

- **A.** \(a_c\) remains the same
- **B.** \(a_c\) increases by a factor of \(3\)
- **C.** \(a_c\) decreases by a factor of \(3\)
- **D.** \(a_c\) increases by a factor of \(9\)
- **E.** \(a_c\) decreases by a factor of \(9\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/20990/*