the speed of light in air ______ the speed of light in water

Question

a. faster than

b.equal to

c.slower than

d. depends on the temp

Answer 1

The speed of light in a medium is given by 

 

v = c/n

 

where

 

c = speed of light in a vacuum

n = refractive index of the medium

 

For smaller n, v is larger.  Conversely, for higher n, v is lower.

 

For air, n ≅ 1.000

For water, n ≅ 1.333

 

The refractive index of air is less than the refractive index of water, so the speed of light in air is higher than the speed of light in water.  The correct answer is (a).

Answer 2

slower than. Choice C.