The speed of light in a certain material is measured to be 2.2 × 10⁸ m/s.What is the index of refraction of this material? (c = 3.0 × 10⁸ m/s) A)1.1 B)1.2 C)1.4 D)1.6 E)1.8

Question

Quizplus · Accepted Answer

The index of refraction is defined as the ratio of the speed of light in a vacuum to the speed of light in the material. 
n = c/v, where c is the speed of light in vacuum and v is the speed of light in the material. 
Substituting the given values, 
n = c/v = (3.0 × 10^8 m/s)/(2.2 × 10^8 m/s) = 1.36 
Therefore, the closest choice is C, 1.4.

The Speed of Light in a Certain Material Is Measured