Find a waves length given the electric field?

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SUMMARY

The discussion focuses on determining the wavelength of an electromagnetic wave characterized by the electric field equation E = (3.1 x 10^5 V/m) * k-hat * cos(ky - (12.65 x 10^12 rad/s)t). The wave number k is defined as k = 2π/λ, where λ represents the wavelength. To find the wavelength, one must identify the wave number k from the given equation, which can be derived from the angular frequency ω = 12.65 x 10^12 rad/s and the relationship between wave speed, frequency, and wavelength.

PREREQUISITES
  • Understanding of electromagnetic wave equations
  • Familiarity with wave properties such as wavelength and frequency
  • Knowledge of trigonometric functions and their applications in wave motion
  • Basic understanding of the speed of light in a vacuum
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  • Calculate the wavelength using the relationship λ = v/f, where v is the speed of light and f is the frequency derived from the angular frequency.
  • Explore the concept of wave number and its significance in wave mechanics.
  • Investigate the relationship between electric and magnetic fields in electromagnetic waves.
  • Learn about the implications of wave behavior at fixed points in space and time.
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Homework Statement



an electro magnetic wave has an electric field given by E= (3.1x10^5 v/m)*khat*Cos[ky-(12.65*10^12 rad/s)t]

Homework Equations



k = 2pi/(lambda)


The Attempt at a Solution



I do not know what to sub in for y and t or how to set the equation equal to something so i can solve. So I am pretty much stuck.
 
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This is a traveling wave so its amplitude is a function of position and time. At any given instant of time (suppose you cold freeze time), then the amplitude would look like a cosine curve fixed in space.

On the other hand, if you choose a fixed location (y) then the amplitude at that location will vary according to a cosine function of time, the wave moving through that location at the speed of light. You can pick ANY location along the line of the wave and this will be true. What do you think might be a convenient location? What's the equation for the signal at that location?
 

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