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# Physics/Index of Refraction

Question
How does trigonometry correspond to the index of refraction?

Thank you~

As a light waves passes from one medium into another the angle between the in coming light ray <1 and the normal (a line drawn perpendicular to the interface) to the interface (the boundary between the two mediums) changes direction according to Snell's Law such that the product of the index of refraction of the first medium n1 multiplied by the sin of the angle in the first medium <1 is equal to the product of the index of refraction in the second medium n2 multiplied by the sine of the angle in the second medium <2:
n1*sin(<1)=n2*sine(<2)
n, the index of refraction, is defined to be the ratio of the speed of light in a vacuum c to the speed of light in a particular medium s:
n=c/s
The index of refraction is always greater than 1 because the speed of light in a vacuum c is always greater than the sped of light in a given medium.

Physics

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#### James J. Kovalcin

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I am teaching or have taught AP physics B and C [calculus based mechanics & electricity and magnetism] as well as Lab Physics for college bound students. I have a BS in Physics from the University of Pittsburgh and a Master of Arts in Teaching from same. I have been teaching physics for 34 years. I am constantly updating my skills and have a particular interest in modern physics topics.