---
title: "Two thin coins are made from identically the same metal, but one coin has triple the diameter of the other. What is the ratio of the moment of inertia of the large coin compared to the small coin? Take the axis of rotation to be perpendicular to the coin and through its center; assume that the coins have the same thickness. Hint: The moment of inertia of a solid disk about its center is \\(\\frac{1}{2} M R^{2}\\)."
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url: "https://nerd-notes.com/ubq/104411/"
date_modified: "2025-11-02T13:36:12+00:00"
---

# Two thin coins are made from identically the same metal, but one coin has triple the diameter of the other. What is the ratio of the moment of inertia of the large coin compared to the small coin? Take the axis of rotation to be perpendicular to the coin and through its center; assume that the coins have the same thickness. Hint: The moment of inertia of a solid disk about its center is \(\frac{1}{2} M R^{2}\).

Two thin coins are made from identically the same metal, but one coin has triple the diameter of the other. What is the ratio of the moment of inertia of the large coin compared to the small coin? Take the axis of rotation to be perpendicular to the coin and through its center; assume that the coins have the same thickness. Hint: The moment of inertia of a solid disk about its center is \(\frac{1}{2} M R^{2}\).

- **A.** \( 243 \)
- **B.** \( 81 \)
- **C.** \( 27 \)
- **D.** \( 9 \)
- **E.** \( 3 \)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/104411/*