# Physics Help ?

I have an assignment due tomorrow night and I am trying to figure out the following problem - I have looked online for hints but I cannot find a problem with wavelength and angle given.

Light with a wavelength of 737 nm enters quartz glass at an angle of 25.0 degree. Determine the angle of refraction and the wavelength of the light in the quartz glass.

Thank you in advance!

### 1 Answer

- Andrew SmithLv 73 months agoFavorite Answer
The question lacks a CRITICAL piece of information. The refractive index of quartz glass. ( And we must assume that it is entering from air and that the angle is measured from the normal.)

Snell's law. n2 sin( theta2) = sin( theta1) -> theta2 = 1/n2 * sin(25)

The wavelength is inversely proportional to the speed. ie it is inversely proportional to n2 -> lambda = 737 / n2 ( where n2 is the refractive index of quartz glass)

Thank you! I knew something had to be missing - I too assumed air but definitely a terribly put together question.