waves

• wave speed = frequency X wave length
• wave parts

  • peak - top
  • trough - bottom
  • amplitude - height
  • wavelength - distance between 2 peaks
• transverse wave

  • oscillates at 90 degrees to the direction of wave
  • sound
  • all EM spectrum waves
  • seismic s-waves
• longitudinal waves

  • oscillations parallel to direction of wave travel
  • sound
  • seismic p-waves
• total internal reflection

  • angle of incidence = angle of refraction
• refraction - change of direction / speed of a wave from one medium to another
• more dense material

  • ray slows down
  • bends towards the normal
• less dense material

  • ray speeds up
  • bends away from the normal
• ultra sound - frequency above human hearing

  • above 20,000 hertz
• seismic waves

  • travel through earth
  • result of an earthquake / volcanic eruption
  • seismometre to detect
  • understand internal structure of earth
  • detect earthquakes early
• p waves

  • travel through solid / liquid / gas
  • longitudinal
  • fast
• s waves

  • travel only through solids
  • transverse