Question

The speed of light in vacuum is exactly 299,792,458 m/s. A beam of light has a wavelength of 651 nm in vacuum. This light propagates in a liquid whose index of refraction at this wavelength is 1.16. What is the speed of this light in the liquid? Give an answer in 108 m/s. Pay attention to the number of significant figures.

Answer 1

`v=2.58*10^8m/s`

Step-by-step explanation:

The index of refraction is equal to the speed of light c in vacuum divided by its speed v in a substance, or
`n=(c)/(v)`. For our case we want to use
`v=(c)/(n)`, which for our values is equal to:

`v=(c)/(n)=(299792458m/s)/(1.16)=258441774.138m/s`

Which we will express with 3 significant figures (since a product or quotient must contain the same number of significant figures as the measurement with the least number of significant figures):

`v=2.58*10^8m/s`