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demonstrations:3_oscillations_and_waves:sound_waves:beat_notes:start [2019/03/25 18:07]
demoroom
demonstrations:3_oscillations_and_waves:sound_waves:beat_notes:start [2020/03/06 18:57] (current)
demoroom
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 ====== Beat Notes ====== ====== Beat Notes ======
  
-{{tag> interference acoustics oscillations_and_waves frequency ​unlocated}}+{{tag> interference acoustics oscillations_and_waves frequency ​located}}
  
 <WRAP box right> <WRAP box right>
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 ===== Purpose ===== ===== Purpose =====
  
-Demonstration of the constructive and destructive interference ('​beating'​) observed when two nearly identical frequencies are played together. ​+Demonstration of the constructive and destructive interference ('​beating'​) observed when two nearly identical frequencies are played together. ​[[https://​en.wikipedia.org/​wiki/​Beat_(acoustics)|Relevant Wikipedia page]]
  
 ===== Apparatus ===== ===== Apparatus =====
  
   * Pair of tuning forks   * Pair of tuning forks
 +  * (Optional: Vernier Labpro, Microphone, and computer with LoggerPro)
  
 // Or alternatively://​ // Or alternatively://​
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 ===== Setup ===== ===== Setup =====
  
-  * Two organ pipes, one with a variable frequency adjustment are sounded together. By moving ​the frequency adjustment ​of one pipe to obtain a frequency close to the other pipe will result with beats. +  * Place the pair of tuning forks with resonance boxes on a table so that the open ends of the boxes face the audience. Now, strike both of the forks with a rubber mallet. If the adjustable ​fork is damped ​so that it's frequency is slightly ​different than the other, beats will be heard. 
-   +  * If you are using a LabPro, attach it to the microphone sensor and a computer ​with LoggerPro open. Set data collection for few seconds and display the graph of the beating frequencies 
-  * Two identical ​tuning forks on resonance boxes should be placed ​on the demonstration bench so that the open ends of the boxes are angled to face the audience. If one fork is now damped slightly with a damping piece attached ​to it, beats will be heard.+ 
 +  * If you do this with a pair of organ pipes, you will need an assistant. Get your assistant ​to sound the non-adjustable pipe continuouslyand begin sounding the adjustable pipe yourself. Adjust the pipes so that they are sounding nearly the same note, and beats should ​be heard.
  
 ===== Notes ===== ===== Notes =====
  
 +The frequency of the '​beats'​ tone that you hear is equal to the difference between the two other frequencies being played. If the frequencies are sufficiently close, you may not hear any beats at all, and if they'​re too far apart the beats will have a high enough frequency to be heard as a [[wp>​combination tone]].
  
 +The basic principle is an extension of superposition.
  
 <WRAP group> <WRAP group>
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 </​WRAP>​ </​WRAP>​
 <WRAP tablewidth 100%> <WRAP tablewidth 100%>
-| **Location** | ---- |+| **Location** | T4 |
 | **Maker** | Unknown | | **Maker** | Unknown |
 | **Current State** | Working | | **Current State** | Working |
demonstrations/3_oscillations_and_waves/sound_waves/beat_notes/start.1553537228.txt.gz · Last modified: 2019/03/25 18:07 by demoroom