The refractive index of water with respect to vacuum is $\frac{4}{3}$ and refractive index of vacuum with respect to glass is $\frac{2}{3}$ If the speed the speed of light in glass is $2 \times 10^8 ms^{-1}$, find the speed of light in (i) vacuum, (ii) water.
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Refractive index of water w.r.t air $=\frac{4}{3}$$\text{n}_\text{wa}=\frac{\text{v}_\text{a}}{\text{v}_\text{w}}$
$\frac{4}{3}=\frac{3\times10^8}{\text{v}_\text{w}}$
On calculating we get velocity of light in water -$-2.25 \times 10^8 m / s$
$\frac{4}{3}=\frac{3\times10^8}{\text{v}_\text{w}}$
On calculating we get velocity of light in water -$-2.25 \times 10^8 m / s$
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