Sound: Standing Waves and Resonance | Physics in Motion
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- เผยแพร่เมื่อ 19 มิ.ย. 2024
- We visit a university orchestra to help us understand wave interference and how resonance affects waves moving through different types of air columns and strings. We explore how to find various resonant frequencies using the wave velocity equation in combination with an equation that relates the wavelength of a wave to the length of a string, or a closed, or open-ended tube.
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So basically when 2 waves of same amplitude and opposite directions meet, we get a standing wave.
These standing waves are what are required for resonance.
Now resonance can be compared to father pushing his child on a swing. Only when the swing has travels to its extreme position can the father push it. If it choses to push it at any other instance of time, the swing may loose its height or in this case amplitude.
Resonance increases amplitude.
In closed wind instruments or string tied to one end, the condition for resonance is that we need a node at closed and antinode at open end. So only 1/4th or 3/4th... waves could be created and thus they have the formula L = n λ /4 where L is length of string/pipe and n is odd
Whereas in In open wind instruments or string tied to both ends, the condition for resonance is that we need 2 nodes at both sides. So only 1/2 or 1 or 1.5 waves could be created and thus they have the formula L = n λ /2 where L is length of string/pipe and n is any no.
THIS HELPED ME UNDERSTAND TYSM
Thank you, now i finally understood!
Glad it helped!
Finally I got the right understanding of these disturbances. They're not hard as I thought 😊
9:44. The cello A string is actually 220 hertz.
loved the video❤
the best！！
In relation to my previous comment, I should point out that light is focused by means of a lens on the center of a vibrating horizontal string that is fixed at its two ends. The light is made to go through a vertical slot, and with a second lens, it is focused again on a rotating mirror which projects it unto a screen, but it is not clear, how the waveform of the vibrating point is registered, or else, how it is made visible. Professor White says that that if various modes of vibration are active, the resulting compound wave can be observed.
The best
Hello.
In Harvey E. White's Modern College Physics, an experiment for visualizing the waveform of a string is described. It involves the use of a rotating mirror. I do not entirely understand the related figure (Fig. 20 E in the 2002 spanish edition). I've looked for videos in TH-cam that might show how this experiment is carried out, but not one of those that I've found seems to correspond to the mentioned description. I would very much appreciate any hint you might kindly provide.
Thank u
I wonder how 3D cematic molecular sound, laser or microwave resonance printing could be achieved
to have stuff in 3 to 8 minutes of a molecular gas resin chamber.
Simply thausands of mini laser diodes shaping a 1x1 meter platform.
What it does is actually attract and fuse theese plastic molecules by the electromagnetic wave point
wich has micro focal heating points.
Imagine a 1x1 meter Box.
Each side has directional wave loudspeaker or microwave emitters, so that theese could create a standing wave on 0,3 inch or so.
Inside the box, wich is a sealed container for gases, a certain blend of molecular plastic structures is sprayed in as a gas.
A computer program calculates and establishes with the omnidirectional emitters of microwave and /or liner loudspeaker module platforms
to ultrasonicly create a focal cavitation point in the gas, causing theese to melt microscopically on the molecular level.
My this theoretically glueing plastic molecules in floating in the air.
Other perhaps better option could be 3D Microwave printing of Plastic gas.
Meaning 6 sides of the inner cube would need to have mininled sized emitters
calibratable in sinus and amplitude able to move a focal point inside a line to create a wave resonance point at any point inside the box.
Could perhaps build a plastic table in 5 minutes after the inner wave chamber was filled with molecular plastic gas
At 7:24, the chart showing the "String Harmonic Progression" has an error starting with the 5th harmonic. The used 4 in the denominator instead of 5. There is a similar mistake for the 6th harmonic.
I'm confused. At 1.22 she says it isn't about how hard you hit it it's about the rhythm in which you hit it. But he doesn't hit it in a certain rhythm , he just hits it once. And then after that she says that through resonance the amplitude can change which means it can get louder or softer, but then in the example the sound it softer when he hits it lighter, and the sound is louder when he hits it harder. So clearly it is about how hard he's hitting it. How is this showing resonance?
The resonance frequency on that specific instrument (tubular bell) its determined by the length of the tube, you can research more about that on air column physics.
On the video, the demonstration is that on percussion instruments, the elements that produces musical notes (or resonant frequencies) that dont vary their shape, stays the same no matter how you hit It. You can definitely change the timbre, the volume, but the Frequency stays the same.
Rhythm was a poor choice of word there. The point was that whether you hit it hard or soft, it resonates at the same frequency. Loud or quiet is about vibration amplitude.
Creating objects by sound.
Sound points fusing plastic or other material gas
Well, you wouldn't be creating Matter with sound but you could shape things like water, snow, ice, salt rocks and sand grains into various shapes using sound pressure waves. It's actually very interesting and sound can be used to achieve lift and levitate things and also lots of other real neat stuff that I could tell ya about but I won't because then I would have to poke your eyes out And you probably like your eyeballs so I shouldn't tell ya about Screech Sabers &
silent weapons for quiet wars;^D.
Hi Purity Lady, what does it mean when sparks are manifesting around the rim of the bell of My Saxophone?
Example:
Select object
Press GO
Enjoy object like a table, cup or complex tool in 5 minutes out of a device that looks like a microwave, that composed theese objects of gas, waves and heat.
yooo cobra kai