If the index of refraction of glass is 1.8 and the speed of light in air is 3.00 · 108 m/s, what is the speed of light in that glass? (Round answer to nearest hundredth.)

1.67 * 10^8

6.00 * 10^-9

5.40 * 10^8

Index of refraction of glass (n) = 1.8

Speed of light in air (c) = 3 x 10E8 m/s

Speed of light in glass (v) = ?

We know,

n = c : v

1.8 = 3 x 10E8 : v

Therefore,

v = 3 x 10E8 : 1.8 = 1.666 x 10E8 = 1.67 x 10^8 m/s