The speed of light varies based on the material that the waves are passing through. The refractive index of a material indicates how easily light travels through it compared to how easily light travels through a vacuum. For example, the refractive index of water is 1.33, meaning that light travels 1.33 times faster in a vacuum than it does in water.
Water has a refractive index of 1.33. Which of the following is true?
light is 1.33 times dimmer in a vacuum than it is in water |
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light travels 1.33 times faster in a vacuum than it does in water |
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light is 1.33 times brighter in a vacuum than it is in water |
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light travels 1.33 times slower in a vacuum than it does in water |