Question #a1b5c

1 Answer
Sep 18, 2017

The speed of light in a vacuum is a constant and is #300 000 000 " m/s"#, or #3.0*10^8" m/s"#.

The speed of light decreases in a given medium.

Explanation:

The speed of light in a vacuum is constant because there are no atoms to absorb the electromagnetic radiation.

The speed of light decreases in a given medium such as air. For an example, the speed of light in air at sea level is #299,792,458" m/s"#.

I hope that helps!