Question

Light is travelling at a speed of `2.20*10^8` `m`/`s` through alcohol. What is the index of refraction of alcohol?

Answer 1

`1.36`, rounded to two decimal places.

Explanation:

Refractive index `n` of a material is a dimensionless number. It tells us how light propagates through that material.

`n -= c/ v`
where `c` is the speed of light in vacuum `=3xx10^8ms^-1`, and `v` is the phase velocity of light in the material.

Inserting given values we get refractive index of alcohol as
`n = (3xx10^8)/ (2.2xx10^8)`
`=>n = 1.36`, rounded to two decimal places.