Explanation on how to arrive at equation for EM wave?

In summary, the electric field component of an EM wave can be described by the equation E=E_{0}cos(kx-\omega t), which is a travelling wave with a constant shape and velocity ω/k. This form is different from the standard sinusoidal equation and describes a wave that varies with both time and space.
  • #1
serverxeon
101
0
It is known that the electric field component of the EM wave is given by
[itex]E=E_{0}cos(kx-\omega t)[/itex]

How do I arrive at such a form?
It is quite different from the standard sinusoidal equation of [itex]y=Acos(\omega t+\varphi)[/itex]

Any guidance?
What does the [itex]kx-\omega t[/itex] describe physically?
 
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  • #2
serverxeon said:
It is known that the electric field component of the EM wave is given by
[itex]E=E_{0}cos(kx-\omega t)[/itex]

How do I arrive at such a form?
It is quite different from the standard sinusoidal equation of [itex]y=Acos(\omega t+\varphi)[/itex]

Any guidance?
What does the [itex]kx-\omega t[/itex] describe physically?

Your 'standard form' describes a wave that is constant at all values of x and only varies with t. The given form describes a 'travelling wave' that varies not only with time but with space as well. It has a constant shape but moves at velocity ω/k.
 

Related to Explanation on how to arrive at equation for EM wave?

1. What is an EM wave?

An EM (electromagnetic) wave is a type of wave that is composed of both an electric field and a magnetic field, which oscillate perpendicular to each other and travel through space at the speed of light.

2. How do you arrive at the equation for an EM wave?

The equation for an EM wave is derived from Maxwell's equations, which describe the relationship between electric and magnetic fields. By combining these equations and using mathematical principles, we can arrive at the equation for an EM wave, which is: E = cB, where E is the electric field, B is the magnetic field, and c is the speed of light.

3. What does the equation for an EM wave represent?

The equation E = cB represents the strength of the electric field (E) in relation to the strength of the magnetic field (B) in an EM wave. It also shows that the electric and magnetic fields are directly proportional to each other and are both dependent on the speed of light (c).

4. Can you explain the significance of this equation?

The equation for an EM wave is significant because it shows the fundamental relationship between electric and magnetic fields and how they work together to create a wave. It also helps us understand the behavior of EM waves and how they travel through space at the speed of light.

5. How is the equation for an EM wave used in practical applications?

The equation E = cB is used in various practical applications, such as in the development of wireless technologies like Wi-Fi and Bluetooth, as well as in the transmission of radio and television signals. It is also crucial in understanding the properties of light and how it behaves as an electromagnetic wave.

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