Waves

• Transverse waves has vibrations perpendicular to the direction of energy transfer.

  Eg. All EM waves, S waves, Waves in water
• Longitudinal waves have vibrations parallel to the direction of energy transfer.

  Eg. Sounds waves, P waves
• wave speed (m/s) = frequency (Hz) x wavelength (m)

  v = f x λ
• Wave basics:

  • Amplitude = height
  • Wavelength = length of 1 wave
  • Frequency = the number of waves that pass a point per second

  
• Use an oscilloscope to measure the speed of sound
• To measure frequency:

  • Float a cork in a ripple tank
  • When the cork is at the top of a 'bob' start the stopwatch
  • Count how many times the cork 'bobs' in a set time (eg. 20 seconds)
  • Divide the number of times by the time to get the number of 'bobs' per second
• To measure the wavelength:

  • Take a picture of a ripple tank with a ruler on top
  • measure the distance of 1 wave
• To measure the wave speed:

  • Speed = distance travelled by a wave / time taken