Info on soundwaves and overtones

  • Thread starter Thread starter djef
  • Start date Start date
AI Thread Summary
The discussion centers on the concept of soundwaves and overtones, specifically the first harmonic in a tube open at one end. It explains that the first resonant frequency contains only a quarter of a wave, leading to the conclusion that the wavelength is four times the length of the tube. This is due to the wave needing to complete a full cycle, which requires going up, returning, going down, and returning again. The closed end of the tube acts as a node, while the open end serves as an antinode. Understanding this relationship clarifies why the wavelength is four times the tube's length.
djef
Messages
8
Reaction score
0
hallo all,

while reading some info on soundwaves and overtones I found the following statement on wikipedia:
"The first overtone is the first allowed harmonic above the fundamental frequency (F1).

In the case of a system with two different ends (as in the case of a tube open at one end), the closed end is a node and the open end is an antinode. The first resonant frequency has only a quarter of a wave in the tube. This means that the first harmonic is characterized by a wavelength four times the length of the tube."

now I want to know why it is like this:
The first resonant frequency has only a quarter of a wave in the tube. This means that the first harmonic is characterized by a wavelength four times the length of the tube.

Why the 4 ?

how do they get that?
 
Physics news on Phys.org
happy new year!

djef said:
The first resonant frequency has only a quarter of a wave in the tube. This means that the first harmonic is characterized by a wavelength four times the length of the tube.

Why the 4 ?

how do they get that?

Hallo djef! :wink:

The wave has to go up :rolleyes:, come back, go down :frown:, and come back, to do one wavelength.

For a tube closed at one end, the wave only has time to go up :rolleyes:

that's 1/4 of the wavelength. :smile:
 


oh yes, indeed, thanks a lot tiny-tim
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top