Question

speed of light in vacuum is _____​

Answer 1

Answer:

3×10⁸ m/s (approximately)

Answer 2

Answer:

approximately 300,000 kilometers per second

Explanation:

Light travels at approximately 300,000 kilometers per second in a vacuum, which has a refractive index of 1.0, but it slows down to 225,000 kilometers per second in water and 200,000 kilometers per second in glass.

maybe helpfull......