The refractive indices of a certain liquid for red violet colours are `1.325` and `1.333`, respectively. Find the difference between the speeds of the rays of these two colours in the liquid.

Explanation

Data: `n_(r) = 1.325, n_(v)= 1.333, c=3 xx 10^(8) m//s`
`n_(r)=c/v_(r)` and `n_(v) = c/u_(v) therefore v_(r) = c/n_(r)` and `u_(v)=c/n_(v)`
Since, `n_(r) lt n_(p), v_(r) - v_(v)= c(1/n_(r)-1/n_(v))`
`=(3 xx 10^(8))(1/(3.25) - 1/(3.36))`
`=(3 xx 10^(8) xx 0.008)/(1.325 xx 1.333) = 1.359 xx 10^(5) m//s`