The refractive index of glass is $1.5$. Calculate the speed of light in glass. The speed of light in air is $3.0\times {10^8}\ ms^{-1}$.

Given:

Refractive index of glass = $1.5$

Speed of light in air = $3.0\times {10^8}m/s$

To find: Speed of light in glass.

Solution:

From the formula for refractive index, we know that-

$Refractive\ index\ of\ a\ medium=\frac {Speed\ of\ light\ in\ air}{Speed\ of\ light\ in\ medium}$

For glass:

$Refractive\ index\ of\ glass=\frac {Speed\ of\ light\ in\ air}{Speed\ of\ light\ in\ glass}$

Substituting the given value, we get-

$1.5=\frac {3.0\times {10^8}m/s}{Speed\ of\ light\ in\ glass}$

$Speed\ of\ light\ in\ glass=\frac {3.0\times {10^8}m/s}{1.5}$

$Speed\ of\ light\ in\ glass=2.0\times {10^8}m/s$

Thus, the speed of light in glass is $2.0\times {10^8}m/s$.

Tutorialspoint

Simply Easy Learning

Updated on: 10-Oct-2022

241 Views

Kickstart Your Career

Get certified by completing the course

Get Started