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SOUND WAVE GettyImages-172646826-57dd5dbc5f9b586516e37e4c - Coggle Diagram

- - - - phenomenon which change of pressure due to velocity of an object greater than velocity of sound (supersonic)
        
        example = velocity of :airplane: > velocity of sound (343 m/s)
        
        sin a = velocity of sound / velocity of object
        
        Mach no ,Ma = 1/ sin a=velocity of object /velocity of sound
      - when shock wave happens,observer experienced sonic boom
        
        sonic boom = compressional wavefront piled up, create very high pressure zone
        
        compressional region reach observer at same time
        
        every compression followed by rarefaction
        
        higher pressure region will be followed by lower pressure region immediately
        
        a very loud noise created (similar to explosion sound) ~100-120 dB
      - important remark :!::
        
        there will be time delay of sonic boom after shock waves due to higher pressure followed by lower pressure region
        
        sonic boom generates greater amount of energy
        
        higher pressure region caused by compressional wave pilled up
        
        waves getting compressed and merge into single shock wave because they cannot get out each others quickly enough
    - - phenomenon where perceived frequency of source different from actual frequency due to relative motion of observer and source
        
        example : an ambulance with siren on passes through a man
      - relative velocity
        
        :star:(source)
        
        towards to
        
        :diamonds: (observer)
        
        = f> fo
        
        :star:(source)
        
        away from
        
        :diamonds: (observer)
        
        = f <fo
      - formula , f = fo (v+_ vo/v -+ vs) , note that if :star:/ :diamonds: not moving , add 0 to vs or vo
        
        f= original frequency
        fo=perceived frequency
        vo= velocity of observer
        vs= velocity of source
        v=velocity of sound ( 343 m/s)
        
        (+) if toward :star:/:diamonds:
        
        (-) if away from :star:/:diamonds: