Bottle. sound by blowing across the top

  • Thread starter Thread starter Goodver
  • Start date Start date
  • Tags Tags
    Sound
Click For Summary
Blowing across the top of a bottle creates sound due to the formation of standing waves in the air inside, while blowing into the bottle does not produce sound at the correct frequency for resonance. The turbulence generated by the air flow across the edge of the bottle creates a vortex pattern, leading to periodic pressure disturbances that propagate as sound waves. The walls of the bottle contain the air vibrations, allowing them to resonate effectively. In contrast, blowing into the bottle fails to generate the necessary turbulence and resonance. Understanding these principles clarifies the mechanics of sound production in bottles.
Goodver
Messages
101
Reaction score
1
sound created by blowing across the top of the bottle produces sound due to standing waves created on air inside the bottle.

why blowing inside the bottle does not produce sound but only across?

how vibrations created on air inside the bottle propagate in space as they are separated from outside by the walls of bottle? or the walls of bottle start to vibrate?

thank you
 
Physics news on Phys.org
Goodver said:
sound created
why blowing inside the bottle does not produce sound
It does, but wrong with frequency to resonate.

Goodver said:
how vibrations created on air inside the bottle propagate in space as they are separated from outside by the walls of bottle?
The bottle is open, isn't it?
 
  • Like
Likes 1 person
thanks A.T.

why blowing across the top produces resonance while blowing in not?
 
Goodver said:
thanks A.T.

why blowing across the top produces resonance while blowing in not?

I believe this is to do with turbulence. The air flow is probably more turbulent when you blow across the edge of the bottle.
 
CWatters said:
I believe this is to do with turbulence. The air flow is probably more turbulent when you blow across the edge of the bottle.

Yes. When the edge splits the air flow, it separates and creates a periodically repeating vortex pattern similar to the one seen below. The periodic pressure disturbances propagate as sound waves that can resonate.

https://www.youtube.com/watch?v=bVNvH51CmlE
 
  • Like
Likes 1 person
For simple comparison, I think the same thought process can be followed as a block slides down a hill, - for block down hill, simple starting PE of mgh to final max KE 0.5mv^2 - comparing PE1 to max KE2 would result in finding the work friction did through the process. efficiency is just 100*KE2/PE1. If a mousetrap car travels along a flat surface, a starting PE of 0.5 k th^2 can be measured and maximum velocity of the car can also be measured. If energy efficiency is defined by...

Similar threads

Replies
8
Views
2K
  • · Replies 29 ·
Replies
29
Views
4K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 49 ·
2
Replies
49
Views
5K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 7 ·
Replies
7
Views
1K
Replies
10
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K