Question #56175

1 Answer
Carlos S.
Jan 18, 2018

1.5.

Explanation:

The refraction index #n# is defined as the ratio between the speed of light in the vacuum, #c#, and its velocity in a given medium, #v#; that is:

#n = c/v#.

Then, using #c = 3.10^8 m/s# and that #v = 2x10^8 m/s# (I am assuming the #10^8# factor here, because I believe you might have forgetten something in your question):

#n = (3.10^8)/(2.10^8) = 1.5.#

However, if the velocity is, indeed, #v = 2 . 10 m/s# you simply have to use the correct value in the equation above. :)

Hope it helped!

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