Musical Instruments- Guitar String Harmonic Frequencies

Musical Instruments

Everybody loves listening to music especially music that made by musical instruments such as Guitars. Can you imagine Physics and Music ever being related? well now you can find out how musical instruments like a guitar can help you understand harmonic frequencies. How 
does 
doubling,
 tripling, and quadrupling 
the 
length 
of 
a
guitar
 string
 effect 
the
 collection
 of harmonic
 frequencies
 at 
which 
it naturally
 vibrates
 and 
the 
speed at
 which waves travel
 within 
it?

Materials Required

  • Wave 
driver
  • Digital function
 generator
  • 
Lab
poles
  • Wire
  • 500‐g 
hooked mass.
  • Clamps
  • Pulley

Procedure

An approximate 1.5‐meter length of steel wire is secured to a clamp on a lab pole at one end of the lab table. A 500‐g hooked mass is secured to the other end of the wire and draped over a pulley at the opposite end of the table. A wave machine is set up by connecting the output of a digital function generator to a wave driver.

The wave driver is attached to the wire at a distance of 1.20 m from where the wire is attached to the lab pole. The frequency of the generator is adjusted in order to force the wire to vibrate with its second harmonic pattern. The frequency and harmonic number is recorded. The frequency is slowly increased until the third and the fourth harmonic standing wave patterns are established in the wire.

The frequencies of these harmonics are recorded. Measurements are carefully repeated for the second, third and fourth harmonics for vibrating wire lengths of 0.90 m, 0.60 m, and 0.30 m from the pole. The data are then analyzed in order to determine the answer to the question raised in the Purpose of the lab.

Purpose of the Experiment

To determine how a doubling, tripling and quadrupling of the length of a string effects the collection of harmonic frequencies at which it naturally vibrates and the speed at which waves travel within in it.


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