What factors affect the frequency of harmonics in a soda bottle?

[bahtiyar]

I saw a question
"If you blow across the open end of a soda bottle and produce a tone of 250 Hz, what will be the frequency of the next harmonic heard if you blow much harder?"
the answer is 750 Hz
but I'm curious about "if you blow much harder" part, is it really depends on how much harder you blow or something else?

 

[BvU]

Do the experiment and you'll be the expert !

 

[Asymptotic]

When you run the experiment check how the frequency changes. Jumping an octave is what I'd expect (from 250 Hz to 500 Hz).

 

[mjc123]

I think the point is that it is closed at one end and open at the other; there is a node at the closed end and an antinode at the open end, so it goes from 1/2 wavelength to 3/2 wavelength.

 

[Asymptotic]

I think the point is that it is closed at one end and open at the other; there is a node at the closed end and an antinode at the open end, so it goes from 1/2 wavelength to 3/2 wavelength.

Didn't give that any thought. I believe you have the right of it.

 

[bahtiyar]

isn't that about the speed of sound, if it is right how it much harder blowing effect on it. What is the logic here can anyone explain?

 

[jerromyjon]

isn't that about the speed of sound

The speed of sound is near 750 MPH, 750 Hz is oscillations per second...

 

[Ibix]

isn't that about the speed of sound, if it is right how it much harder blowing effect on it. What is the logic here can anyone explain?

Think about the speeds of the molecules which are needed for each harmonic mode.

 

[jasonRF]

I think this is pretty complicated, since a bottle like that is an example of a Helmholtz resonator. The column of air in the neck of the bottle is acting like the piston, and the air in the main portion of the bottle is acting like the spring. The basic linear theory is pretty simple - it is explained in basic sophomore level physics texts (eg Electromagnetic Vibrations, Waves and Radiation by Bekefi and Barrett). The harmonics are not as easy for me to understand. A quick google search did find an article that may be of interest:
http://iopscience.iop.org/article/10.1088/1361-6552/aa532b/meta

Jason

 

[bahtiyar]

I think this is pretty complicated, since a bottle like that is an example of a Helmholtz resonator. The column of air in the neck of the bottle is acting like the piston, and the air in the main portion of the bottle is acting like the spring. The basic linear theory is pretty simple - it is explained in basic sophomore level physics texts (eg Electromagnetic Vibrations, Waves and Radiation by Bekefi and Barrett). The harmonics are not as easy for me to understand. A quick google search did find an article that may be of interest:
http://iopscience.iop.org/article/10.1088/1361-6552/aa532b/meta

Jason

thank you
the video on the page clearly shows which harmonic occurs depend on the speed of air that we blow. I can't reach the article it requires purchase the article but video was enough for me