Can a 28.5Hz Frequency Cause a Standing Wave in a 6m Long String?

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The discussion revolves around a 6.0m long vibrating string with a source frequency of 16.5Hz and the implications of a different frequency, 28.5Hz, on the formation of standing waves. Participants explore the fundamental frequency and wave speed of the string.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants examine the calculation of the fundamental frequency and wave speed, with some questioning the method used to determine the fundamental frequency. There is also a discussion about whether the 28.5Hz frequency can create a standing wave in the string.

Discussion Status

Some participants have provided alternative calculations and questioned the original poster's approach, indicating a productive exchange of ideas. However, the original poster has not engaged further in the discussion.

Contextual Notes

The thread is noted to be from August 2014, and the original poster has not logged in since, which may affect the continuation of the discussion.

Codav
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1. A string that is 6.0m long is vibrating with three loops in it. The frequency of the source is 16.5Hz.

What is the fundamental frequency of the string?

What is the speed of the waves in the string?

Explain whether or not a source of frequency of 28.5Hz causes a standing wave in the string.
3. Info: 6m long string. Source frequency is 16.5Hz. There are 3 loops.
Find wavelength:
6m/3=2m
Each loop is 2m.
1 loop is half a wavelength.
λ=2*2
λ=4m
Since the frequency is 16.5Hz with three loops, to find fundamental frequency you just divide by three.
16.5/3=5.5Hz
The fundamental frequency is 5.5Hz
Find speed with velocity equation: v=ƒ*λ
v=16.5*4
v=66m/s
The speed of the waves in the string is 66m/s

A source frequency of 28.5Hz would not cause a standing wave in the string because it is not a multiple of the fundamental frequency 5.5Hz.
28.5Hz/5.5Hz=5.182Hz
 
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What's your question? Or do you just want an approval stamp from PF ?
(By the way: I can't find anything wrong with what you write...
except: Hz/Hz is not Hz. The quotiënt is a simple number
:smile:)
 
I think your fundamental freq is wrong, you should be dividing speed by wavelength, not number of loops. Doing this returns fundamental freq as 4.125, which is a multiple of the initial freq (16.5).
 
Tarragon said:
I think your fundamental freq is wrong, you should be dividing speed by wavelength, not number of loops. Doing this returns fundamental freq as 4.125, which is a multiple of the initial freq (16.5).
This thread is from August 2014. The Original Poster has not logged in since August 27th, 2014. It is therefore highly unlikely that you will get a response from them.

Because of its age and lack of evidence that thee OP has any interest in it, I am closing this thread to further posts.
 

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