Question

A light has the wavelength 6000 å in air and 4500 å in water. then the speed of light in water will be

Answer 1

this the answer easy one

Answer 2

Speed of light in water is $\bold{2.25 \times 10^{8} \frac{m}{s}}$

Solution:

Wavelength of light differs in air and water, and speed of light also follows the same which can be calculated as follows,

Given: Wavelength of light in air = 6000       Light wavelength in water = 4500

As we know, $\lambda_{\text {water}}=\frac{\lambda_{\text {air}}}{\mu}$  

$\begin{aligned} \mu &=\frac{\lambda_{\text {air}}}{\lambda_{\text {water}}} \\ \mu &=\frac{6000}{4500} \\ \mu &=\frac{4}{3} \end{aligned}$

Velocity of light in water= $\frac{v e l o c i t y \text { in air }}{\mu}$

Velocity of light in water= $\frac{3 \times 10^{8}}{\frac{4}{3}}$  

Velocity of light in water = $\bold{2.25 \times 10^{8} \frac{m}{s}}$.