The derivation for the speed of electromagnetic waves comes out of Maxwell\'s eq

Question

The derivation for the speed of electromagnetic waves comes out of Maxwell's equations for electromagnetism. For this reason, the speed of an electromagnetic wave depends on electromagnetic constants, v = 1/ mu epsilon (the speed of an electromagnetic wave in vacuum is given the variable c. Some books highlight the equation c = 1/ mu 0 epsilon 0, which is just a special case of this general equation in vacuum.)2 3 In a vacuum, epsilon = epsilon 0 = 8.85 Times 10-12 C2/Nm2 and mu = mu 0 = 4n Times 10-7Tm/A . Calculate the speed of an electromagnetic wave in vacuum.4 In water, an electromagnetic wave has frequency 5 Times 1015 Hz and wavelength 45 nm. By what factor is the speed of this electromagnetic wave slower than the speed of an electromagnetic wave in vacuum? In glass, an electromagnetic wave has frequency 5 Times 1015 Hz and wavelength 40 nm . By what factor is the speed of this electromagnetic wave slower than the speed of an electromagnetic wave in vacuum?

Explanation / Answer

speed of electromagnetic wave=1/sqrt(epsilon*mu)

=2.9986*10^6 m/s

b)as we know, speed of wave=freqeuncy*wavelength

then in water, speed is given as

5*10^15*45*10^(-9)=2.25*10^8 m/s

so factor by which it has been slower=2.9986/2.25=1.3327

c)

as we know, speed of wave=freqeuncy*wavelength

then in glass, speed is given as

5*10^15*40*10^(-9)=2.0*10^8 m/s

so factor by which it has been slower=2.9986/2.0=1.4993

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