Interference and Sound Waves

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Interference and Sound Waves
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Recipe of Music
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Beats
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Important You can not say what frequency is
higher!!!!
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Doppler Effect
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Shock Waves and Sonic Boom
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1. What is the different ways to increase the
   fundamental frequency of a note played on a
   guitar string?
2. An automobile sounding its horn is moving toward
   you at a constant speed. How does the frequency
   you hear compare with that heard by the driver?
3. Why dont we hear beat when adjacent keys on a
   pianop are hit at the same time?

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1. You can tune the frequency of a guitar string
   without changing its length. To tune a flute,
   however, you have to slightly adjust the length
   of the tube. How do you account for this
   difference?
2. Electronic signal generators can produce pure
   sound frequencies with great precision. Why then
   is it so difficult to make an electronic piano
   that sounds like an acoustic piano?

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1. Why is the low E-string on a guitar made of
   thicker wire that the high-E string?
2. Billy and Elaine are holding electric buzzers
   that sound at slightly different frequencies.
   When they are both standing still, the two
   buzzers produce the beat frequency of 4 hertz.
   Elaine begins to run away, and Billy hears the
   beat frequency gradually increase. Whose buzzer
   has the higher frequency? Explain.

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Baby-Quiz

1. On what two places on a guitar string of length L
   could you place you finger to damp out the second
   harmonic? Would the fourth harmonic be damped out
   if you placed your finger at either of these
   locations?
2. What happens to the fundamental frequency of an
   organ pipe as the temperature in the room
   decreases? Explain.
3. The two wires corresponding to one key on a piano
   are out of tune. If we decrease the tension of
   the wire producing the lower frequency, will the
   beat frequency increase, decrease, or stay the
   same?
4. Describe the sounds you would hear if a train
   passed you with its whistle blowing.