(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A plane, harmonic, linearly polarized light wave has an electric field intensity given by

[tex]{E}_z[/tex] = [tex]{E}_0[/tex] cos pi*[tex]10^{15}[/tex]*(t - x/.65c)

while traveling in a piece of glass. Find

(a) The frequency of the light.

(b) Its wavelength.

(c) The index of refraction of the glass.

3. The attempt at a solution

I'm still confused about the argument of the cosine, but I assume that what was within the parenthesis was the real argument. Under this assumption, it fits the form (kx-wt) with some tweaking. The angular frequency w will give me the frequency. I'm pretty sure I need the velocity in order to get the wavelength, and am unsure as to how to find it. Once I get the velocity it will be easy to find the index of refraction.

The problems I ran into:

w=-1 in this case, and so 1/2pi gives me the frequency.

finding velocity of the wave: I used [tex]w^{2}[/tex]/[tex]k^{2}[/tex] = v, however this gives me a value much larger than the speed of light.

Should I just distribute the stuff before the argument? I've never seen a cosine like that. I think that it would be better if it was cos(pi*10^15*(t-x/.65c)) and am confused as to why they didn't do that if that is really what they meant.

Thanks for any help you can provide!

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# Homework Help: Frequency and other properties from E-field

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