Chapter 11, Problem 42R

To determine

To Explain:Under what conditions will an electromagnetic wave travel slower than the speed of light? At the speed of light? Faster than the speed of light?

Answer to Problem 42R

If the density of the medium is higher than the ideal condition, than the speed of the electromagnetic wave is slower than the speed of light.

Explanation of Solution

Introduction:

Electromagnetic wavesorEM wavesarewavesthat are created as a result of vibrations between an electric field and a magnetic field. In other words,EM wavesare composed of oscillating magnetic and electric fields.

If the density of the medium is higher than the ideal condition, than the speed of the electromagnetic wave is slower than the speed of light.

Electromagneticradiation is a type of energy that is commonly known aslight. Generally speaking, we say thatlight travelsinwaves, andall electromagneticradiationtravelsat the samespeedwhich is about $3\times {10}^8\text{m/s}$ through a vacuum.

Speed of electromagnetic wave never goes faster than speed of light.

Conclusion:

Hence, if the density of the medium is higher than the ideal condition, than the speed of the electromagnetic wave is slower than the speed of light.