Question

The speed of light in air is 3×10^ 8ms-1 calculate the speed of light in glass of refractive index 1.6

Answer 1

Need to FinD :-

• The speed of light in glass .

$\red{\frak{Given}}\begin{cases}\sf The\ speed \ of \ light \ is \ 3 * 10^8 \ m/s. \\\\\sf The \ refractive\ index \ is \ 1.6 . \end{cases}$

We know that the refractive index is defined as the speed of light in vacuum to the speed of light in any medium . Mathematically ,

$\sf\longrightarrow \mu = \dfrac{ Speed\ of \ light \ in \ vacuum}{Speed\ of \ light \ in \ med^m }$

• Put on the respective values ,

$\sf\longrightarrow \mu = \dfrac{c}{v} \\\\\\\sf\longrightarrow 1.6 = \dfrac{3*10^8 \ m/s }{v} \\\\\\\sf\longrightarrow v = \dfrac{ 3*10^8 m/s}{1.6} \\\\\\\sf\longrightarrow \underline{\underline{\red{ Velocity _{(glass)}= 1.8\times 10^8 \ m/s }}}$