1.1 Introduction to waves

• All waves transfer energy from one place to another
• $S=$$vt$


  S= Distance (metres)

  v= Speed (m/s)

  t= Times (S)
• Wavelength is the distance between one spot on a wave and the same exact spot on the next.
• Amplitude is the height of the wave from the centre line.

  The bigger the amplitude the more energy the wave possesses.
• Velocity is the distance a wave travels in one second
• Frequency is the number of waves that pass a point in one second.
• Period is the time taken for one complete wave to pass a particular point.
• $f=$$N/t$


  f= frequency (Herz)

  N= Number of waves

  t= times (S)
• $f=$$1/T$


  f = frequency (Herz)

  T = period (s)
• Transverse waves is where the particles making up the wave vibrate at 90 degrees to the direction of wave travel
• Examples of transverse wave include:

  • Water waves
  • Light
  • EM spectrum waves
• A longitudinal wave is a wave in which the particles vibrate along the wave in the same direction.
• • A longitudinal wave is a sound wave
  • They can travel through anything but a vacuum
  • Speed of sound in air is 340 m/s
• Sounds above 20000Hz are called ultrasound
• The bending or spreading out of waves is known as diffraction.