Speed of light slowest in _______.

A
Air

B
Glass

C
Water

D
Never changes

Topic Flashcards

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Question

What is the refractive index (n) of a material, and how is it mathematically defined in terms of the speed of light?

Answer

The refractive index is a measure of how much a material slows down light. It is defined as n = c / v, where c is the speed of light in a vacuum and v is the speed of light in the material.

Question

Rank the following materials from lowest to highest refractive index: Water (n≈1.33), Air (n≈1.00), Glass (n≈1.5). Based on this, in which does light travel fastest and slowest?

Answer

Air (1.00) < Water (1.33) < Glass (1.5). Light travels fastest in air and slowest in glass. A higher n means a lower speed v.

Question

Why does light bend (refract) more sharply when entering glass from air compared to entering water from air?

Answer

Light bends more in glass because the change in speed is greater. Glass has a higher refractive index than water, meaning the light slows down more dramatically, causing a larger change in direction.

Question

What is the speed of light in a vacuum (c)? Approximately what is its speed in a typical glass with n=1.5?

Answer

In a vacuum, c ≈ 3.00 x 10⁸ m/s. In glass, v = c / n = (3.00 x 10⁸) / 1.5 ≈ 2.00 x 10⁸ m/s.

Question

The "optical density" of a material is related to its refractive index. Does a higher optical density mean light travels faster or slower through it?

Answer

Slower. A material with higher optical density has a higher refractive index, which corresponds to a lower speed of light within it.

Mini Quiz

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Is the refractive index of a vacuum exactly 1?

Speed of light slowest in _______.

A
Air

B
Glass

C
Water

D
Never changes

The speed of light is slowest in glass.

Topic Flashcards

Mini Quiz

Related Questions

Speed of light slowest in _______.

A Air B Glass C Water D Never changes

The speed of light is slowest in glass.

Topic Flashcards

Mini Quiz

Related Questions

A
Air

B
Glass

C
Water

D
Never changes