Proving EM Waves Equations: E = Emsin(kx-ωt) and B = Bmsin(kx-ωt)

In summary, the electric field E = Emsin(kx-ωt) and magnetic field B=Bmsin(kx-ωt) satisfy the equations -\frac{\partial B}{\partial x} = \mu_{0}\epsilon_{0}\frac{\partial E}{\partial t} and \frac{\partial E}{\partial x} = -\frac{\partial B}{\partial t}. To solve this, you would start with Maxwell's equations and substitute the given expressions for E and B into the differential equations, taking derivatives and then manipulating the equations to eliminate B_m and E_m.
  • #1
noppawit
27
0
Show that the electric field: E = Emsin(kx-ωt) and magnetic field: B=Bmsin(kx-ωt) satisfy the following equations:

[tex]-\frac{\partial B}{\partial x} = \mu_{0}\epsilon_{0}\frac{\partial E}{\partial t}[/tex]

and

[tex]\frac{\partial E}{\partial x} = -\frac{\partial B}{\partial t}[/tex]


I have no idea about this. Would you please guide me for solving this.

Thanks.
 
Last edited:
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  • #2
Your equations didn't come out properly so we can't help you.
 
  • #3
Sorry for my bad Latex typing. :redface:

I've edited.
 
  • #4
noppawit said:
Show that the electric field: E = Emsin(kx-ωt) and magnetic field: B=Bmsin(kx-ωt) satisfy the following equations:

[tex]-\frac{\partial B}{\partial x} = \mu_{0}\epsilon_{0}\frac{\partial E}{\partial t}[/tex]

and

[tex]\frac{\partial E}{\partial x} = -\frac{\partial B}{\partial t}[/tex]


I have no idea about this. Would you please guide me for solving this.

Thanks.

In a situation like this, the usual procedure is to substitute the two given expressions into the differential equation, take the derivatives and see what happens. As I look at what you've been given (without working it out myself) I think you may have to figure out how to relate [tex] \mu_o \epsilon_o [/tex] to k and [tex] \omega [/tex].
That should get you started. Let us know if you run into trouble.
 
  • #5
AEM said:
In a situation like this, the usual procedure is to substitute the two given expressions into the differential equation, take the derivatives and see what happens. As I look at what you've been given (without working it out myself) I think you may have to figure out how to relate [tex] \mu_o \epsilon_o [/tex] to k and [tex] \omega [/tex].
That should get you started. Let us know if you run into trouble.

Upon reading my previous post, I see a small problem with what I wrote. When you substitute the expressions for E an B into each equation, you'll end up with a [tex] B_m [/tex] on one side and a [tex] E_m [/tex] on the other. That's a nuisance. However, I'll bet you can figure out a way to combine those two equations into one equation and then do the substitution.
 
  • #6
noppawit said:
Show that the electric field: E = Emsin(kx-ωt) and magnetic field: B=Bmsin(kx-ωt) satisfy the following equations:

[tex]-\frac{\partial B}{\partial x} = \mu_{0}\epsilon_{0}\frac{\partial E}{\partial t}[/tex]

and

[tex]\frac{\partial E}{\partial x} = -\frac{\partial B}{\partial t}[/tex]


I have no idea about this. Would you please guide me for solving this.

Thanks.

IIRC, you would start with Maxwell's equations...
 

1. What is the equation for the speed of an electromagnetic wave?

The speed of an electromagnetic wave (c) is equal to the product of the wavelength (λ) and frequency (f): c = λf.

2. How do I calculate the frequency of an electromagnetic wave?

To calculate the frequency of an electromagnetic wave, divide the speed of light (c) by the wavelength (λ): f = c/λ.

3. What is the relationship between frequency and energy in an electromagnetic wave?

The energy (E) of an electromagnetic wave is directly proportional to its frequency (f): E = hf, where h is Planck's constant.

4. How do I determine the wavelength of an electromagnetic wave?

To determine the wavelength of an electromagnetic wave, divide the speed of light (c) by the frequency (f): λ = c/f.

5. Can I use the same equations for all types of electromagnetic waves?

Yes, the equations for electromagnetic waves are universal and can be used for all types of waves, including radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.

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