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vw = fλ
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d = rt |
| sound level |
dB to power
take the difference in the decibels, divide that difference by 10,
relationship between the original sound levels equals 10x power
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intensity of sound (watts/m2)
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| comparison of two intensity values |
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sound level intensity (dB)
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threshold of human hearing (Io = 1 x 10-12 watts/m2)
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| beats |
beat frequency = |f2 - f1|
beat pitch = ½(f1 + f2)
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| speed of sound in dry air |
vw = 331 + 0.6T
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| open-closed pipe |
for the fundamental, A-N
Lpipe = ½ loop = ¼λ
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| open-open pipe |
for the fundamental, A-N-A
Lpipe = 1 loop = ½λ
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EPD = |L1 - L2}
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constructive: mλ
m ∈ {0, 1, 2, 3, ....} remember L1 can equal L2
destructive: ½(2m - 1)λ
m ∈ {1, 2, 3, ....}
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listener moving
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Δf / f = v / vw
approaching: f' = f + Δf
receding: f' = f - Δf
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source moving
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Δλ/λ = v / vw
approaching: λ' = λ - Δλ
receding: λ' = λ + Δλ
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