Glass Harp - pitch

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Glass harp reportedly first built around 1730 in southern Germany. In the mid 18th century, became popular throughout Europe and became a common musical instrument.

Educational phase: motivation

 

Required aids+

  • wine glasses
  • colored water / wine

 

Experiment instructions+

E112_S001 Fill the glasses with water, each to a different level.
E112_S002 We sort glass according to level.
E112_S003 We cross fingers for less throats filled glasses and listen to high notes.
E112_S004 Then we cross fingers for more throats filled glasses and listening to low tones.
E112_S005 The picture of surface waves can be observed oscillations caused by the walls.
 

Explanation+

When passing your finger over the edge of the glass there is a resonance of thin glass, which then sound waves in the air. Height of the resulting tone is dependent on level, the higher the level, the lower the tone.
 

Experiment video+

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Physical interpretation+

Then three fingers moistened rim glasses. There is a resonance of thin glass, which then form the acoustic standing waves of air. The sound of the human ear as vznímá tone of a certain frequency. The wavelength of the tone depends on the distance the free water surface and the edges of the glass.
 

Application in practice+

Playing the glasses :)
 

Note+

Interest: http://fyzmatik.pise.cz/158117-sklenena-harfa.html
 

Control issues and challenges+

  • Which glass is needed to expreriment work?
  • This experiment can be done for example with a pint of beer?

 
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This experiment has been added 14.4.2012 by Jan Krejčí and since then have 2153 visits.
 
3.6.2014 21:44 © Krejčí Jan
 
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