Light enters glass, where it travels at 2×10⁸ m/s instead of 3×10⁸ m/s. Estimate the index of refraction of this glass.

Physics I / Geometric Optics: Reflection and Refraction

Practice question · Estimate

Light enters glass, where it travels at $2\times10^{8}$ m/s instead of $3\times10^{8}$ m/s. Estimate the index of refraction of this glass.

Estimate on a scale from 1.0 (1) to 3.0 (3).

Hints

The index compares vacuum speed to material speed: $n = c/v$ .
$n = 3\times10^{8} / 2\times10^{8}$ .

Show the answer

1.5 (answers within ±0.1 count)

Why

$n = 1.5$ , typical window glass. All of refraction follows from this slowdown: wavefronts entering at an angle pivot like a marching band stepping onto mud, the side that slows first swings the line around.

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Light enters glass, where it travels at 2×1082\times10^{8}2×108 m/s instead of 3×1083\times10^{8}3×108 m/s. Estimate the index of refraction of this glass.

Practise Geometric Optics: Reflection and Refraction

More questions on Geometric Optics: Reflection and Refraction

Light enters glass, where it travels at $2\times10^{8}$ m/s instead of $3\times10^{8}$ m/s. Estimate the index of refraction of this glass.