sound and seismic waves

• describe motion of sound waves 


  longitudinal travelling through particles as vibrations through compressions and rarefactions
• describe sound waves for human hearing

  vibrations in ear converted to electrical impulses to the brain
• give range of human hearing

  20hz to 20000hz
• describe ultrasound 


  sound waves with frequency higher than 20000hz
• give uses of ultrasound

  medical and industrial imaging
• describe use of ultrasound

  time taken for reflection at boundaries can determine distance to boundary
• describe p waves 


  longitudinal wave that can pass through solids and liquids and faster
• describe s waves 


  transverse waves that can pass through solids and slower
• describe use of seismic waves 


  measure time taken for seismic waves to determine internal structure of earth