Tagged Questions
1
vote
0answers
46 views
Fourier Transform of ribbon's beam Electric Field
I have a monochromatic ribbon beam with $E(x)e^{i(kz-\omega t)}$ being the electric field's amplitude. I want to show that the lowest order approximation in terms of plane waves is
...
2
votes
2answers
227 views
Why are AC quantities represented by sine waves always?
Usually we use a sinusoidal wave form to represent a alternating quantity. Why not a cosinusoidal wave or a ramp wave form?
In sine wave forms we can indicate the maximum and minimum amplitude and ...
1
vote
3answers
89 views
How to design an experiment that shows that a rectangular pulse can be expressed as a series of infinite sinusoids?
Is it possible to design a physical experiment that shows that a time limited signal, such as a rectangular pulse is composed of infinite continuous sine/cosine waves?
7
votes
2answers
136 views
Does light have timbre?
Timbre is a property associated with the shape of a sound wave, that is, the coefficients of the discrete Fourier transform of the corresponding signal. This is why a violin and a piano can each play ...
0
votes
2answers
3k views
Can the equation $v=\lambda f$ be made true even for non sinusoidal waves?
The known relation between the speed of a propagating wave, the wave length of the wave, and its frequency is
$$v=\lambda f$$
which is always true for any periodic sinusoidal waves.
Now consider:
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4
votes
3answers
348 views
Physics of a guitar
I understand that when you pluck a guitar string, then a bunch of harmonic frequencies are produced rather than just the frequency of the desired note.
If this is true, why does C2 sound so different ...
4
votes
2answers
1k views
Physical interpretation of Parseval's theorem
I have read that Parseval's theorem, relating the norm of a function $f$ and the norm of its Fourier transform $g(k)$:
\begin{equation}
\int |f(x)|^2 dx=\int|g(k)|^2 dk
\end{equation}
has the ...
4
votes
2answers
176 views
Does a finite wave necessarily have to be non-monochromatic in reality?
Does a finite wave necessarily have to be non-monochromatic in reality, or is that implication just a result of the mathematical analysis? I always wonder at these sort of things that come out of a ...
