---
title: "A beam of light travels through a vacuum at a speed of \\(c = 3.0 \\times 10^8 \\text{ m/s}\\) before entering a block of crown glass with an index of refraction of \\(n = 1.5\\). What is the speed of light as it travels inside the glass block?"
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url: "https://nerd-notes.com/ubq/116759/"
date_modified: "2026-08-04T06:09:25+00:00"
---

# A beam of light travels through a vacuum at a speed of \(c = 3.0 \times 10^8 \text{ m/s}\) before entering a block of crown glass with an index of refraction of \(n = 1.5\). What is the speed of light as it travels inside the glass block?

A beam of light travels through a vacuum at a speed of \(c = 3.0 \times 10^8 \text{ m/s}\) before entering a block of crown glass with an index of refraction of \(n = 1.5\). What is the speed of light as it travels inside the glass block?

- **A.** \(1.5 \times 10^8 \text{ m/s}\)
- **B.** \(2.0 \times 10^8 \text{ m/s}\)
- **C.** \(3.0 \times 10^8 \text{ m/s}\)
- **D.** \(4.5 \times 10^8 \text{ m/s}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/116759/*