Question

Two objects, Object A and Object B, need to be identified. Object A's index of refraction is determined to be 1.77, and Object B's index of refraction is determined to be 1.333. Knowing this information, which of the following must be true? A. Light can pass through Object A faster than it can pass through Object B.
B. The optical density of Object A is lower than the optical density of Object B.

C. Light can pass through Object B faster than it can pass through Object A.

D. The optical density of Object B is higher than the optical density of Object A.

Answer 1

Penn Foster Students:  Light can pass through Object B  faster than it can pass through Object A

Answer 2

C. Light can pass through Object B faster than it can pass through Object A.

Explanation:

The index of refraction of a material is given by

$n=\frac{c}{v}$

where

c is the speed of light in vacuum

v is the speed of light inside the material

From the equation, we see that there is an inverse relationship between n (the index of refraction) and v (the speed of light in the material): therefore, the lower the index of refraction, the higher the speed of the light.

In this problem, object A has a refractive index of 1.77, while object B has a refractive index of 1.333: since object B has a lower refractive index, light travels faster in object B.