a. 1.94 x 108 m/s
Refractive index is called index of refraction, measure of the bending of a ray of light when passing from one medium into another.
It is represented by :
n = c/v
Where n is refractive index , c is speed of light and v is phase velocity of light.
Given,
Refractive index of amber is 1.55,
Speed of light through a vacuum is 3.00 x 10⁸m/s
By computing the values,
1.55 = 3 x 10⁸/v
v = 1.94 x 10⁸ m/s
Therefore,
1.94 x 10⁸ m/s is the speed of light through amber.
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