P11 - Wave Properties

• Wave behaviour is common in both natural and man-made systems
• Waves carry energy from one place to another and can also carry information
• Designing comfortable and safe structures such as bridges, houses and music performance halls requires an understanding of mechanical waves
• Modern technologies such as imaging and communication systems show how we can make the most of electromagnetic waves
• Transverse wave

  Oscillations travel perpendicular to the direction of energy transfer
• Longitudinal wave


  Oscillations travel parallel to the direction of energy transfer
• Example of a Transverse wave

  • Ripples on a water surface
• Example of a Longitudinal wave

  • Sound waves travelling through air
• A wave is a disturbance that propagates, waves transfer energy without transferring matter
• Amplitude


  The maximum displacement of a point on a wave away from its undisturbed position
• Wavelength


  The distance from a point on one wave to the equivalent point on the adjacent wave
• Frequency


  The number of waves passing a point each second
• Period


  The time taken to produce a wave
• As the frequency of a wave increases


  The wavelength decreases
• As the wavelength of a wave increases


  The frequency decreases
• Wave speed


  The speed at which the energy is transferred (or the wave moves) through the medium
• Peak


  The highest point on a wave
• Trough


  The lowest point on a wave
• Rarefaction


  A region in a longitudinal wave where the particles are furthest apart
• Compression


  A region in a longitudinal wave where the medium is compressed
• Oscilloscope


  Displays and measures changing signals like sound waves and alternating current
• Using a ripple tank

  1. Set up the ripple tank

  2. Adjust the height of the wooden rod

  3. Switch on the lamp and motor

  4. Measure the length of waves

  5. Count the number of waves passing a point in ten seconds

  6. Calculate the speed of the waves
• Variables


  • Independent variable = frequency, f
  • Dependent variable = wavelength, λ
  • Control variables: Same depth of water, Same temperature of water
• Frequency.


  The higher the frequency of the sound wave the higher the pitch.
• Amplitude


  The higher the amplitude of the sound wave the louder the wave.