Question

If the speed of light in water of refractive index 4/3 is 2.25×10^8 m/s, what will be the speed of light in vacuum?

Answer 1

Explanation:

The speed of light of vacuum 3\times 10^8 m/s3×10

8

m/s

Explanation:

Speed of light in water v=2.25\times10^8 m/sv=2.25×10

8

m/s

The refractive index of glass is n=4/3

Speed of light is glass c

The refractive index = Speed of light in Vaccum /speed of light in any medium (Water)

$$\begin{lgathered}n=\frac{c}{v} \\c=n \times v\\c=\frac{4}{3} \times 2.25 \times 10^8\\c=3\times 10^8 m/s\end{lgathered}$$

Therefore the speed of light of vacuum $$3\times 10^8 m/s$$