# waves and sound

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1-A tunning fork has a frequency of 440Hz. The string of a violin and this tuning fork, when sounded together, produce a beat frequency of iHz. From these two pieces of information alone, is it possible to determine the exact frequency of the violin string?... I feel like this is a trick question since my first thought is yes since i could just put them into my formula for beat frequency and obtain the other frequency, but this is too obvious.

2-The tension of a guitar string is doubled. Does the frequency of oscillation also double? If not, by what factor does the frequency change? Specify whether the change is an increase or decrease... I don't know how to answer this one..:(

• waves and sound -

well, the violin string could be above or below the fork frequency.

If you tighten the string of course the frequency goes up. I am sure your physics book has the derivation
frequency = (1/2L)sqrt (F/u)
where L is the length
F is the tension
u is mass per unit length
if you double f, frequency goes up by sqrt 2 or about 1.41

• waves and sound -

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