The refractive index of water is 1.33 and the speed of light in air 3 × 108 ms–1. Calculate the speed of light in water.
Given that;
Refractive index (μ) = 1.33 
;
Speed of light in air(c) = 3 x 108;
Speed of light in water =?
We know that
⇒ 
⇒ 
⇒ v= 2.25 × 108m/s.
Hence speed of light in water is 2.25 × 108m/s.
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