GS-1 Physical Sciences Question 17

[Berman878951]

I understand how to answer this question intuitively, but I am having a bit of a difficult time understanding the ratio set up in the answer.

Why is the correct ratio v1/v2 = n2/n1?

Shouldn't it be v1/v2 = n1/n2?

My only guess is that since n = c/v, n is inversely proportional to v, therefore the ratio is set up like that...

Any help would be appreciated.

Thanks!

[jellywing_2058]

[kevinsmith6086]

I thought the refractive index was based on the medium and not the wave entering, therefore n should be equal for each wave and the velocity change due to the difference in wavelengths....because n for water is 1.33 and it doesn't matter if red, green, blue etc. light shines through it....thoughts?

[karonta6617]

I was thinking the same thing. The refractory index is a property of water and it shouldn't change.

How is anyone else looking at this.

[heatherole1204]

I thought the same thing, so I looked it up on wiki, and this is what they say:

"Refractive index of materials varies with the frequency of radiated light. This results in a slightly different refractive index for each color. The cited values of refractive indices, such as 1.33 for water, are taken for yellow light of a sodium source which has the wavelength of 589.29 nanometers"
(Wikipedia, July 2011)

Who'da guessed?