Waves in Air, Fluids and Solids

• 2 types of waves

  transverse and longitudinal
• are ripples on a water surface transverse or longitudinal

  transverse
• what do longitudinal waves show

  areas of compression and rarefaction
• are sound waves transverse or longitudinal

  longitudinal
• what is amplitude

  maximum displacement of a point on a wave away from its undisturbed position
• what is wavelength

  distance from a point on one wave to equivalent point on the next wave
• what is frequency

  number of waves passing a point each second
• what is wave speed

  speed that energy is transferred through the medium
• period equation

  1 / frequency
• wave speed equation

  frequency x wavelength
• how can waves be reflected

  boundary between two different materials
• how can waves be absorbed/transmitted

  boundary between two different materials
• how can sound waves travel

  through solids - causes vibrations
• how does sound work

  sound waves cause ear drums and other parts to vibrate - conversion of sound waves to vibrations of solids works over limited frequency range which restricts limit of human hearing
• human hearing range

  20 - 20,000 hz
• what are ultrasound waves

  frequency higher than upper limit of human hearing range
• what can time taken for ultrasound reflections to reach a detector be used to determine

  how far away a boundary is
• what does boundaries, ultrasound reflections and detectors allow ultrasounds to be used for

  medical and industrial imaging
• how are seismic waves produced

  earthquakes
• what are p-waves

  longitudinal seismic waves - travel at different speeds through solids and liquids
• are s-waves transverse or longitudinal

  transverse
• can s-waves travel through a liquid

  no
• what do p-waves and s-waves provide evidence for

  structure and size of the earth
• what is echo sounding used for

  uses high frequency sound waves to to detect objects in deep water and measure water depth