Question

If light has a speed of 122,000 mps in a transparent medium, what is the index of refraction of the medium? A. n = 1.52

Answer 1

Answer:

$A.\hspace{3}n=1.52$

Explanation:

The refractive index of a medium is a measure to know how much the speed of light within the medium is reduced. It can be calculated with the next equation:

$n=\frac{c}{v}$   (1)

Where:

$c=Speed\hspace{3}of\hspace{3}light\hspace{3}in\hspace{3}vacuum\\n=Refractive\hspace{3}index$

$v=Velocity\hspace{3}of\hspace{3}light\hspace{3}in\hspace{3}the\hspace{3}medium$

The speed of light in the vacuum is approximately 300,000 km/s. In order to work with the same units let's do the proper conversion with the velocity of the medium:

$122,000\frac{mi}{s} *\frac{1.60934km}{1mi}=196339.48\frac{km}{s}$

Finally, replacing the data in (1):

$n=\frac{300,000}{196339.48} =1.527965746\approx1.52$