Well, the nature of harmonic motion is that there is no particular velocity, just a maximum, so even if a molecule had a resonant frequency that made the maximum velocity mach1, the condition would only exist for an instant, just like it would for any frequency that made the maximum speed > mach1.. Only difference is the phase angle where it would occur each period..
If you know what SHM is, and don't see how it relates to sound then I can't help you..
More important than maximum velocity in most applications of SHM is the period.. Its phase/resonance that determines the effectiveness of transfer..
If you know what SHM is, and don't see how it relates to sound then I can't help you.
But, there is no wave, harmonic or otherwise. Just an impulse-like click and that click propagates at the speed of sound.
Or, is there a wave? Does the "wave" arise within the molecular structure of the medium as part of the process needed to make the sound propagate? This is the point in the explanation at which everything seems to stall.
Even if the element that produced the "click" only produces 1 compresson followed by one rarification it is still a wave.
The compression is caused by moving the molecules closer together.
May I suggest that sound is energy detected by the ear.
It is easy to see that hi pressure on the eardrum will move it in. The faster you vibrate a molecule the warmer it gets. You might transmit sound information by rapidly heating and cooling an object.....
This is as close as I get to understanding the sonic boom: When the airplane flies at the speed of sound "sound" energy does not move fast enough to get away from the front of the aircraft. This energy does travel away from the plane mostly perpendicular to the direction of travel. It is this high pressure/energy that we hear as the boom.
A similar shock wave is generated at the rear of the plane but I am less clear on that end.
Lets see how wrong I am this time
3v0
Sound waves are longitudinal waves.. Periodic compressions, and rarefactions comprise a longitudinal wave.. A mass bouncing like a bungy jumper on a spring/elastic can be modelled as a longitudinal wave
Sorry, I thought you'd been through all this stuff, and was just arguing what you didn't catch in school.. I can totally understand not knowing how SHM relates if you're pushing yourself to learn things you aren't supposed to know already.
crashsite : You have me way out on a limb. I'm not speaking from nothing more than my thick head now. Be critical. I can take it.
I just can't believe such a pointless useless thread has gone to five pages?
Okay...rather than simplifying the explanation you seem to be moving closer and closer to the esoteric possibilities. I almost expect the introduction of pixie dust.
I don't know how to properly reply since I'm not sure what you are saying in the first place.
Can you use that intellect to drive your explanation down to the level of us average Joes?
I can see where you might view "May I suggest that sound is energy detected by the ear." as Zen, it was not intended that way.
In regards to how sound propagates. The document I refered to earlier (a page or two ago) is a good place to start. What I originaly missed is that in addition to distance between molecules the is a stiffness/springy-ness constant associated with each material. The articl may contain the entire picture if one took the time to fully understand it. I have not.
The region that is the shock wave exists in a narrow band that moves with the craft producing it. This high energy compression wave travels faster then the speed of sound because it is driven/pushed/pulled? by the craft itself. As compared to the sound leaving a drum or speaker. Neither the drum or the speaker need to move at the speed of sound to produce the compression waves we know as sound. But yet the compression wave move at the speed of sound.
The "subsonic air" behind the shockwave is just run of the mill sound. Outside of the shockwave that is all it can be.
I just can't believe such a pointless useless thread has gone to five pages?
crashsite, (Touché) Moch 1
I guess you forgot my dust particle.
Actually, I do remember your dust particle. I just never quite figured out how it fit into things....
Well then picture all air molecules as a lattice/grid attached on all sides by elastics.. The elastics represent the fact that these particles cannot continue to move in one direction unimpeded because of surrounding molecules, so they will eventually return.. Imagine then being shorter and under more tesion in solids/liquids etc..So, what you seem to be saying is that there is no elemetary explanation for any of the phenomena related to sound and if you're not into it at an advanced engineering level, you're out of luck. I guess I'm not convinced of that.
I know how a car engine works. I know about operation of the carburetor and how the crankshaft moves the pistons to draw in and compress the mixture and how the ignition expands the mixture to move the piston to creat the power. I also know about the crankshaft and camshaft and valves, etc. Actually, I have the FAA A&P License and we learned about this stuff, a lot of which I already knew.
Well then picture all air molecules as a lattice/grid attached on all sides by elastics.. The elastics represent the fact that these particles cannot continue to move in one direction unimpeded because of surrounding molecules, so they will eventually return..
Imagine then being shorter and under more tesion in solids/liquids etc..
Sound is produced by causing local molecules to move and colide with neighbours.. The collisions provide means of propagation chain reaction like, while the elastics represent the returning force.. Think of the elastics as the desire of the substance to retain its current uniformly spread-out state.. In a way it works kind of like those executive clicking pendulum balls..
At any given time velocity, kinetic/potential energy, and momentum of a particle, its frequency of oscillation, and maximum displacement from where it began can be calculated with the wave function.. The wave function doesn't really help explain the concept here at all really, rather it facilitates information gathering if you already understand the concept.. And believe it or not, it all boils down to simple trig functions, because that is the basis of the math for SHM and the wave equation..
Trig functions often act as simple multiplier functions to determine the relevant portion of a maximum value at any point in the cycle..
For instance:
sin(0°) = 0 and sin(90°) = 1 (and between these two extremes it smoothly changes from 0 to 1)
So the math doesn't really help explain the system..
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?