The absolute refractive indices of glass and water are `(3)/(2) and (4)/(3)` respectively. If the
speed of light is `2xx10^(8) m//s`, calculate the speed of light in (i) vacuum, (ii) water.

Explanation

Given: `v_(8) = 2xx10(8) m//s` (Speed of light in glass)
We know, Absolute Refractive Index of a Madium = `{:("Speed of light in Vacuum (c)"),("Speed of light in the Medium "):}`
`n_(g) = (3)/(2), n_(omega)=(4)/(3) rArr n_(g) = (c)/(v_(g)) = c =n_(g)v_(g)`
`rArr c = (3)/(2) xx 2 xx10^(8) therefore c = 3 xx 10 ^(8) .m//s`
(ii) `n_(omega) = (4)/(3) c = 3xx 10^(8) m//s`
`rArr v_(omega ) = (c) /(n_(omega)) = (3xx10^(8) xx3)/(4) = 2.25xx 10^(8) m//s` .