Multiple choice

The speed of light is

  1. 8 x 108 m/s

  2. 3 x 108 m/s

  3. 8 x 108 km/hr

  4. 3 x 108 km/hr
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The speed of light in vacuum is a fundamental constant of nature, approximately 299,792,458 meters per second, commonly rounded to 3 x 10^8 m/s. This value (c) appears in Einstein's equation E=mc^2 and is the maximum speed for any information or matter in the universe. Note the units must be m/s, not km/hr - 3 x 10^8 km/hr would be only about 83,000 m/s, far slower than light's actual speed.

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