# Physics

posted by .

A light ray of wavelength 610 nm is incident
at an angle θ on the top surface of a block of
polystyrene surrounded by water.
Find the maximum value of θ for which the
refracted ray will undergo total internal re-
ﬂection at the left vertical face of the block.
(Assume the refractive index of water is 1.333,
and the refractive index of polystyrene is
1.487.)

I looked for the critical angle and then, since its a right angle just get the angle measure that would equal the incident angle at the top

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See the 1st link below under Related Questions.

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that link just tells you that question is missing, but it doesnt help answer it

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Whether it is a complete answer, I wouldn't know.

You have to scroll down quite a bit for

Physics - drwls, Tuesday, March 23, 2010 at 9:48pm

First you have to look up the index of refraction for water, polystyrene and carbon disulfide. Apparently they have not provided you with those numbers.

You can only get total internal reflection when a light ray tries to enter a medium with a lower index of refraction. That is not what happens in Part 1, so the answer to that one is B.

For the others, get the refractive index, see if Total Internal Reflection is possible, and apply Snell's law if refraction is possible.

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I don't really know what the refractive index is or the Total Internal Reflection, i jst know Snell's law