Indices of refraction when wavelengths are given

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A parallel beam of light containing two wavelengths, 1 = 400 nm and 2 = 650 nm, enters the silicate flint glass of an equilateral prism with an angle of incidence of 49 degrees. At what angle, relative to the normal, does each beam leave the prism?

This seems simple, but previously, I had solved somilar problems when the indices of refraction were given. So, I checked my textbook and it said that to find the indices of refraction use the formula lambda o/ lambda n. So I tried this and divided 589 nm (isn't this the speed of sound in a vacuum??) by 400 nm to get 1.4725. However, I noticed that for the second ray, the index ( 589 nm/ 650 nm) results in a number that is less than one. This cannot be right. Please help me find the indices of refraction so I can continue with this problem!
Thanks

 

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never mind

Never mind, you do not need to help me with this... my teacher just posted the indices on our website now... Thanks anyway!

 

[quicknote]

for reaching out for help with this problem. It seems like you are on the right track with using the formula for indices of refraction (n = lambda o / lambda n). However, the value of 589 nm you are using is actually the wavelength of yellow light in a vacuum, not the speed of sound. The speed of sound is typically measured in meters per second, not nanometers.

To find the indices of refraction for the two wavelengths given in this problem, you will need to use the actual wavelengths of the light in nanometers. So for 1 = 400 nm, the index of refraction would be 1.47 (since 589 nm divided by 400 nm is approximately 1.47). For 2 = 650 nm, the index of refraction would be 1.52 (since 589 nm divided by 650 nm is approximately 1.52).

Once you have the indices of refraction for each wavelength, you can use Snell's law (n1sinθ1 = n2sinθ2) to find the angles at which the beams will leave the prism. Keep in mind that the angle of incidence (49 degrees) will also need to be taken into account when solving for the angles of refraction. I hope this helps and good luck with the rest of the problem!