Questions tagged [vibrations]
640 questions
544
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8 answers
Can I compute the mass of a coin based on the sound of its fall?
The other day, I bumped my bookshelf and a coin fell down. This gave me an idea. Is it possible to compute the mass of a coin, based on the sound emitted when it falls?
I think that there should be a way to do it. But how?
Vinicius L. Beserra
- 5,337
110
votes
7 answers
Why do tuning forks have two prongs?
I believe the purpose of a tuning fork is to produce a single pure frequency of vibration. How do two coupled vibrating prongs isolate a single frequency? Is it possible to produce the same effect using only 1 prong? Can a single prong not…
acadien
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70
votes
8 answers
What is "Induced Atmospheric Vibration"?
The blackout seen today on the Iberian Peninsula has been attributed to a "rare" phenomenon known as "induced atmospheric vibration":
It says that "due to extreme temperature variations in the interior or Spain, there were anomalous oscillations in…
tobalt
- 2,423
47
votes
10 answers
Why do string instruments need hollow bodies?
My textbook states, 'The sound box has a large area, it sets a large volume of air into vibration, the frequency of which is same as that of the string. So due to resonance a loud sound is produced.'
My question is why isn't the air around the…
Hayden Soares
- 726
45
votes
9 answers
Intuitively, what actually is the cause of resonance?
Please don't explain it mathematically. I have been searching for the reason for a long time.
I have watched Walter Lewin's video giving an example of resonance, but I didn't get the reason behind the intuition. I am confused if the reason exists.
Nandani Kumari
- 606
39
votes
3 answers
Why does glass, in spite of being amorphous, often break along very smooth surfaces?
When a crystalline material breaks, it often does so along planes in its crystalline structure. As such this is a result of its microscopic structure.
When glass breaks however, the shapes along which it breaks are typically very smooth as well,…
doetoe
- 9,484
36
votes
3 answers
Theory behind patterns formed on Chladni plates?
In this video of vibrating Chladni plates we can see small sand particles align themselves into different interesting patterns (also shown in the image below) which correspond to some particular vibrations.
What is the theory behind this fact? Are…
Beni Bogosel
- 685
31
votes
4 answers
Why does a large train cause the ground to shake?
I work in a 4 story building that is approx. 150 feet away from a set of train tracks. When a large (40+ car) freight train goes by, the shaking in the building is perceptible. As I've watched the train go by, there does not appear to be any side…
Nick DeVore
- 413
29
votes
2 answers
In counting degrees of freedom of a linear molecule, why is rotation about the axis not counted?
I was reading about the equipartition theorem and I got the following quotations from my books:
A diatomic molecule like oxygen can rotate about two different axes. But rotation about the axis down the length of the molecule doesn't count. - Daniel…
user36790
24
votes
2 answers
Vibrational anharmonic coupling and noise-induced spontaneous symmetry breaking in a hexagonal finite mechanical lattice
Happy holidays, everyone! The following is part question, part visual gallery, and part classical mechanics problem. Inspired by snow over the weekend I began simulating the vibrations of the following hexagonal lattice system:
The 271 purple dots…
DumpsterDoofus
- 10,699
24
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7 answers
If sound passes through material, vibration is produced. So are electromagnetic waves produced too?
Sound means vibration of molecules and vibration produces electromagnetic waves. So, this means that sound produces electromagnetic waves directly.
Is this possible?
23
votes
4 answers
Magnetic field changes induced by vibrating electric guitar string
Here is a picture (from a paper by Feinberg and Yang in the Journal of the Acoustical Society of America) of an electric guitar string vibrating (mostly in the $y$ dimension) near a permanent magnet.
The steel guitar string is causing the magnetic…
Wandering Logic
- 846
23
votes
5 answers
Why do harmonics occur when you pluck a string?
When you energise a taut string, the following resonant modes of vibration occur:
Plotting on the frequency domain, you can see their corresponding frequencies:
But what is the underlying physical principle? Why does this happen?
Is there any way…
P i
- 341
21
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3 answers
Non-resonant but efficient frequencies
I understand that if the frequency of a driving force coincides with the natural frequency of an oscillator (say a pendulum), the rate at which energy is transferred to the same is maximized. However, there may be other frequencies that are not so…
Sierra
- 527
16
votes
2 answers
Can the vibrations from the Earth affect gravitational wave detectors?
I was very interested in gravitational wave detectors and how they work exactly. From what I know they set up two lasers with mirrors set up to cancel each other out. Then if movement is detected from gravitational wave changes then light from the…
Simoa
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