Among the substances listed, in which one does a beam of light travel at the highest speed?

(1 point)
Responses

Water
Water

Air
Air

Glass
Glass

Plastic
Plastic
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1 answer

A beam of light travels at the highest speed in air. While light travels fastest in a vacuum, among the substances listed (water, air, glass, and plastic), air has the lowest refractive index, which means light travels through it faster than through the other materials.