Question

    What is the speed of light in air?

    A 3 × 10⁶ m/s Correct Answer Incorrect Answer
    B 3 × 10⁸ m/s Correct Answer Incorrect Answer
    C 3 × 10⁴ m/s Correct Answer Incorrect Answer
    D 3 × 10⁵ m/s Correct Answer Incorrect Answer

    Solution

    Light travels in a straight line. Light in the air is 1.0003 times slower than light in a vacuum, which slows it all the way down from 299,792,458 meters per second to 299,702,547 meters per second. That's a slowdown of 89,911 meters per second, which looks like a lot but is only three ten- thousandths of the speed of light. The speed of light in the air is 3 x 108 m/s.

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