Standing Waves in a String - Hanging Motor 



 

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 Code Number :   3B22.10

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Reprinted by permission of Dick Berg, University of Maryland, for use on this website.

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Condition :   Excellent  
Principle :   Standing Waves on a String. 
Area of Study :  Acoustics   
Equipment :   Motor with battery pack on a fishing swivel, bright colored string.
Procedure :   Start the motor and let it hang from the end of the string.  Adjust the length of the string until standing waves are visible.  Up to seven nodes should be obtainable.  NOTE:  The motor must be balanced around the center of mass for this to work well.
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   References

W-122, "DC Motor on String", DICK and RAE Demo Notebook.

Arbor Scientific, "Simple, Inexpensive Standing Wave Kits Get The Entire Class in on The Act", p. 2.

Chris Chiaverina, "Inexpensive Standing Wave Apparatus", The Newsletter of the Wisconsin Association of Physics Teachers, Number 8, March 1999.



Mail Questions and Comments to:  Dale Stille