WEBVTT
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This is College Physics
Answers with Shaun Dychko.
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A Light Ray is traveling
from air into water.
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So it goes from a medium of
index of refraction of 1.00
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to a medium with an index
of refraction of 1.33
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and we can use Snell's Law to verify
that the angle of refraction *Theta two*
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has to be less than the angle
of incidence *Theta One*
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and so that means this upper path is
what the light is going to follow.
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So *n1 sine Theta One*
equals *n2 sine Theta Two*.
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That's Snell's Law and we can solve for
*Theta two* by dividing both sides by *n2*
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and then we get *sine Theta Two*
is *n1 sine Theta One* over *n2*
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and now since *n2* is greater than *n1*.
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So the refraction of water is greater than
the initial index of refraction in air.
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That means that this is going to be greater
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sorry, this is going to be
less than *sine Theta One*
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because *sine Theta One* is getting
multiplied by a fraction is less than one
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because the denominator is
bigger than the numerator there.
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So *sine Theta Two* is going to
be less than *sine Theta One*
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since the denominator *n2* is greater
than the numerator factor *n1*
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and with *sine Theta two* being
less than *sine Theta One*
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that means *Theta Two* is less than *Theta One*
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and that's true for this upper path.