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demonstrations:3_oscillations_and_waves:sound_waves:wave_cancellation_trombone:start

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demonstrations:3_oscillations_and_waves:sound_waves:wave_cancellation_trombone:start [2019/02/14 23:33]
127.0.0.1 external edit
demonstrations:3_oscillations_and_waves:sound_waves:wave_cancellation_trombone:start [2020/02/13 23:13]
demoroom
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 ====== Wave Cancellation Trombone ====== ====== Wave Cancellation Trombone ======
  
-{{tag>acoustic ​interferometer ​needs_review untagged unlocated}}+{{tag> interferometer ​acoustics interference oscillations_and_waves located}}
  
 <WRAP box right> <WRAP box right>
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 ===== Description ===== ===== Description =====
  
-Classes Used: PHYS 101153 +Consists of a pair of U-shaped tubes. One of them fits over the otherso that the length of tube on that side may be adjusted in a way that's similar to a trombone slide. In the center of the bottom tube a speaker is mounted, with a thick piece of rubber tubing used to make the join. In the center of the top tube a horn is mounted. ​
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- +
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 ===== Purpose ===== ===== Purpose =====
  
 +This demo illustrates very clearly the phenomenon of interference in sound waves. It's particularly effective because it does so in a way that can be easily heard by an entire lecture hall. It can be thought of as an '​acoustic interferometer',​ so it would work well to explain how laser interferometers work. 
  
 ===== Apparatus ===== ===== Apparatus =====
  
 +  * Wave cancellation trombone 
 +  * [[demonstrations:​9_equipment:​av_receiver_amplifier:​start|AV Amplifier]] 
 +  * [[demonstrations:​9_equipment:​oscilliscopes_and_function_generators:​function_generator:​start|Function generator]]
  
 ===== Setup ===== ===== Setup =====
  
-sit the trombone on top of the speaker and connect the speaker to a function generator ​(3 kHz works best)    ​+Make sure the trombone ​is firmly set on top of the speaker and connect the speaker to a function generator. 3kHz works well((3kHz is is near the peak for human frequency sensitivity. Essentially,​ we'​re ​best at hearing that frequency.))
  
-( PS : When the input signal is of the frequency of 3 kHz, the first destructive interference happens at the distance of 3 cm, and the first constructive interference happens at the distance of 6 cm , the second destructive interference is at the distance of 9 cm , all those three points can be easily demonstrated from the trombone. ​   +When the input signal is of the frequency of 3 kHz, the first destructive interference happens at the distance of 3 cm, and the first constructive interference happens at the distance of 6 cm , the second destructive interference is at the distance of 9 cm, all those three points can be easily demonstrated from the trombone. ​   ​
  
-By sliding the trombone out, you can observe where destructive interference occurs. A neat thing you could have students do is given the speed of sound and frequency, have them find this sliding distance. ​ ​Updated on: 01/06/15+By sliding the trombone out, you can observe where destructive interference occurs. A neat thing you could have students do is given the speed of sound and frequency, have them find this sliding distance.
  
 ===== Notes ===== ===== Notes =====
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 </​WRAP>​ </​WRAP>​
 <WRAP tablewidth 100%> <WRAP tablewidth 100%>
-| **Location** | ---- |+| **Location** | S3 |
 | **Maker** | Unknown | | **Maker** | Unknown |
 | **Current State** | Working | | **Current State** | Working |
demonstrations/3_oscillations_and_waves/sound_waves/wave_cancellation_trombone/start.txt · Last modified: 2020/02/13 23:13 by demoroom