Question

the absolute refractive indices of glass and water are 4/3 and3/2 respectively.If the speed of light in glass is 2*10raised to power8 m/s , calculate speed of light in 1)vaccum 2)water.

Answer 1

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:-
ng = 3/2
nw = 4/3
 Absolute Refractive Index of a medium = Speed of light in vacuum/Speed of light in the medium Speed of light in glass = 2 x 108m/s 
Speed of Light in Vacuum = (3/2) x 2 x 108 m/s = 3 x 108 m/s 
Speed of light in water = (3 x 108 m/s)/(4/3)                                        = 2.25 x 108 m/s