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Key Equations

Key Equations

speed of sound v=fλv=fλ
intensity I=PAI=PA
sound intensity I=(Δp)22ρvwI=(Δp)22ρvw
sound intensity level β (dB)=10 log10(II0)β (dB)=10 log10(II0)
Doppler effect observed frequency (moving source) fobs=fs(vwvw±vs)fobs=fs(vwvw±vs)
Doppler effect observed frequency (moving observer) fobs=fs(vw±vobsvw)fobs=fs(vw±vobsvw)
beat frequency fB=|f1f2|fB=|f1f2|
resonant frequencies of a closed-pipe resonator fn=nv4L, n=1,3,5...fn=nv4L, n=1,3,5...
resonant frequencies of an open-pipe resonator fn=nv2L, n=1,2,3...fn=nv2L, n=1,2,3...