posted by Hanu2012 .
Brain buster: A laser sends red light of wavelength 650 nm from air into water in a swimming pool. The index of refraction of the water is 1.33.
(a) What wavelength will the light have in the
(b) What colour would light of this wavelength appear if it were in air?
(c) Why does a swimmer under the water see the light as red?
index of refraction = c/v=λ(vac)/λ(substance)
λ(water) =λ(air)/n=650 nm/1.33=489 nm.
This is the wavelength of violet light
The swimmer sees the red-orange color since our eyes detect the frequency of the light