All Questions
Tagged with signal-processing waves
59
questions
2
votes
1
answer
86
views
Doppler effect on non-periodic signals
I would like to understand what's happening to a signal emitted from a moving source and arriving to a moving receptor. But, when I am looking on internet about Doppler effect, I can only find ...
- 123
0
votes
2
answers
377
views
Superimposed Waves
This question has been bothering me for a very long time.
Imagine a wire carrying electric current. It carries two alternating current (AC) signals of different frequencies (say $50$ Hz and $60$ Hz). ...
- 101
0
votes
1
answer
103
views
How to solve this problem involving the "longest interval"?
The problem is shown as follows:
If one wants to make a digital record of sound such that no audible information is lost, what is the longest interval, $\Delta t$, between samples that could be ...
1
vote
1
answer
317
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Why do people study plane wave in wave physics?
I have recently been studying a structure for high sound absorption. There are a lot of literature on similar design, where all of them are using the plane wave as an input to the structure. I have ...
- 171
2
votes
3
answers
313
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Can a sound wave begin with rarefaction?
Some digital recording samples (audio files) of recorded acoustic sounds present sound waves which begin with rarefaction. Is this an actual phenomena that can occur or is it a result of sound ...
- 23
0
votes
0
answers
75
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Are Huygens wavelets just a geometric method for understanding how a wave moves forward or are they an actual thing?
Wavelets are emitted from every point on a wave towards all directions is what I read on a book but on another book I read Wavelets are emitted towards the same direction of the wave. And They create ...
- 11
0
votes
1
answer
182
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Superposition of waves whose wavelengths are continuous
I know how to find the resultant waves when finitely or countably many waves are superimposed but how do I find the wave equation when there are infinitely many waves whose wavelength is continuous? ...
user183683
3
votes
1
answer
70
views
Sound an amplifier makes when you plug / unplug a cable [closed]
When you plug, unplug or even touch a jack cable of an aplifying system with speakers, one can hear a low-pitch sound that is of roughly always the same frequency, which does not seem to depend on the ...
- 2,469
0
votes
2
answers
735
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Low frequency wave ability to penetrate object
as shown in this em wave spectrum image, the lower the frequency the better a wave ability to penetrate object.
https://c479107.ssl.cf2.rackcdn.com/files/20642/area14mp/pvgrynkw-1361853572.jpg
my ...
- 11
0
votes
0
answers
61
views
Low frequency waves influence of high frequency waves
If I have a 20 MHz surface wave travelling along a material, and then introduce a 50 or 100 Hz wave source, will there be a noticeable difference to the output?
(Surface acoustic wave type device, ...
- 219
-1
votes
2
answers
35
views
How can I send a wave towards something and have it respond with a specific value?
Imagine a bat, for example. It uses its echo-location to send waves which get reflected back and thus return information about the surroundings. I want to do the same thing, but instead of just ...
- 1,183
1
vote
1
answer
2k
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What is the difference between collimating, waveguiding, attenuating, and polarizing? [closed]
What's the difference between collimating, waveguiding, attenuating, and polarizing? Are they related on any level at all?
- 472
20
votes
6
answers
19k
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Why are cosine and sine functions used when representing a signal or a wave? [closed]
Actually, in the mathematics sine and cosine functions are defined based on right angled triangles. But how will the representation of a wave or signal say based on these trigonometric functions (we ...
- 339
1
vote
3
answers
1k
views
Does a square (or any non-sinusoidal) wave a definite wavelength?
I'm currently reading/studying the FLP and I have a question regarding waves. In a chapter about QM, Feynman says that any short wave train doesn't have a definite wavelength. I understand this, ...
- 79
0
votes
2
answers
106
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Meaning of $v_\mathrm{source}$ in the Doppler effect
The Doppler equation is given by
$$f_{observed} = \frac{c+v_r}{c+v_s} \cdot{ f_{emitted}}$$
Does $v_s$ refer to the velocity of the source, relative to the receiver at the time the wave (now at the ...
- 21