Question

Light enters from air to dense flint glass with a refractive index of $1.65$. What will be the speed of light in flint glass?

Answer 1

Step-1: Given

The refractive index of flint glass, n = $1.65$

The speed of light in air, c = $3\times {10}^8\frac{m}{s}$

The speed of light in flint glass, v =?

Step-2: Calculation

Calculating the speed of light in flint glass,

The refractive index, $n=\frac{c}{v}$

$$\begin{gathered} 1.65=\frac{3\times {10}^8}{v} \\ v=\frac{3\times {10}^8}{1.65} \\ v=1.81\times {10}^8\frac{m}{s} \end{gathered}$$

Hence, the speed of light in flint glass is $1.81\times {10}^8\frac{m}{s}$.