Faster Light/Longer Wavelength?

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rls303

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Hi, I was doing this FL through BR, and I am a bit confused as to why the answer, I always thought that faster speeds of light have shorter wavelengths and higher frequencies, somewhere from my Physics class! If anyone can help clarify this for me, I would really appreciate it! :)

Here is the passage.
"If light passes from Medium A with an angle of incidence of 40° to the normal into Medium B with a refracted angle of 30° to the normal, what changes are observed in the speed and wavelength of the light in the two mediums?
answer:
It is faster and has a longer wavelength in Medium A than in Medium B.
C is the best answer. Because the angle of refraction is smaller than the angle of incidence, we know that the light ray is bent toward the normal as it passes from Medium A into Medium B. That means Medium B must be denser than Medium A, so the speed (v) of the light ray slows down slightly, although its frequency (f) remains constant. "



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Frequency always stays the same when a wave changes media. you know from the question that c increases (use snell's law to prove it). So in order for frequency to stay constant, lambda also has to increase.
 
Frequency always stays the same when a wave changes media. you know from the question that c increases (use snell's law to prove it). So in order for frequency to stay constant, lambda also has to increase.
I always thought that the c value is always 3e8, and it will never change it is only your v that can change?
 
hey, ISOprop is right; the frequency doesn't change with changing medium.

I think isoprop meant to say that the speed of the light, v, in the new medium has changed.
 
hey, ISOprop is right; the frequency doesn't change with changing medium.

I think isoprop meant to say that the speed of the light, v, in the new medium has changed.

Oh I see. So the frequency is an intrinsic property that won't change, but the wavelength can change for the light depending on the medium.

I remember an equation from my physics travels:

lambda'=lambda/n

This kinda follows that logic, right?

Many thanks to both of you! :)
 
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