Frequencies of fundamental standing waves

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Homework Help Overview

The discussion revolves around the frequencies of fundamental standing waves in closed-end air columns, particularly focusing on the relationship between the length of the columns and their corresponding wavelengths and frequencies.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the implications of column height on sound speed and frequency, questioning whether the problem pertains to closed-end air columns and the reasoning behind the relationships between length, wavelength, and frequency.

Discussion Status

Some participants provide feedback on the clarity of reasoning and suggest that the original poster reconsider their assumptions about the speed of sound in relation to the height of the water column. There is an ongoing exploration of the concepts involved, with no explicit consensus reached yet.

Contextual Notes

Participants are navigating the nuances of sound propagation in different mediums and the implications of column height on frequency, indicating a need for clearer definitions and understanding of the underlying principles.

ardour

Homework Statement


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Homework Equations


Harmonics equations

The Attempt at a Solution


So, I got (A), which is the answer key is correct, but I'm not sure whether my reasoning is right or not. Would this be considered a closed-end air column question? Anyways, according to the length-wavelength relationships for the harmonics (which can be seen here: http://www.physicsclassroom.com/class/sound/Lesson-5/Closed-End-Air-Columns), an increase
in length will produce an increase in wavelength. Since both columns have the same height of water in them, the speed of sound through both should be the same, right? This means that the taller column will have a lower frequency than the shorter column, which will need a higher frequency to compensate for the shorter height, making the answer (A) f_1. Is my reasoning correct?
 
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ardour said:
Since both columns have the same height of water in them, the speed of sound through both should be the same, right?
That's not the reason. The speed of sound in air as well as in water is the same regardless of the length of the medium in which it travels. These are simply two pipes with one end closed having different lengths.
 
Ok, I understand. Given the rest of the explanation though, is it correct?
 
Your explanation is not clear, but you are on the right track. However, the statement
ardour said:
Since both columns have the same height of water in them, the speed of sound through both should be the same, right?
implies that if the the height of water is different, the speed of sound will be different. Why should the speed of sound depend on the height of the water column? Try rewriting your explanation to make it more clear. Doing that will help you clarify your ideas in your mind.
 

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