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Saturday, October 11, 2014

Index of Refraction Problems

Category: Physics

"Published in Newark, California, USA"

A ray of light strikes a water surface at an angle of incidence of 40°. What is the angle of refraction in the water? 

Solution:

The given problem is about refraction of light in which the speed of light will change as it passes through the material. There's a bending of ray of light also in the material. To illustrate the problem, it is better to draw the figure as follows

Photo by Math Principles in Everyday Life

According to Snell's Law, the index of refraction is inversely proportional to angle of refraction. The higher the value of index of refraction, the smaller the angle of refraction is. 


From the Table of Index of Refraction, the index of refraction of air at 20°C is 1.000 and water at 20°C is 1.333. Therefore, the angle of refraction in the water is











Take the inverse sine on both sides of the equation, we have






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