复旦大学《大学物理》课件（英文）-第19章 Sound waves(1).pdfVIP免费

Chapter19Soundwaves19-1PropertiesofSoundwaves19-2Travelingsoundwaves19-4Powerandintensityofsoundwaves19-3*Thespeedofsound19-5Interferenceofsoundwaves19-6*Standinglongitudinalwaves19-7*Vibratingsystemandsourcesofsound19-8Beats19-9TheDopplereffectWhenwediscusssoundwaves,wenormallymeanlongitudinalwaveinthefrequencyrange20Hzto20,000Hz,thenormalrangeofhumanhearing.Forsimplification,wewillconsiderthesoundwavein1Dcase.19-1ProperitesofsoundwavesFig19-2InFig19-2,asthepiston(活塞)movesbackandforth,italternatelycompressesandexpands(使稀薄))theairnexttoit.Thisdisturbancetravelsdownthetubeasasoundwave.xxxxvmu0P0mSmmpx),(),(txtx0+=),(),(txPPtxP0+=It...