Properties and types of waves: Waves: Physics: GCSE (9:1)

• Waves


  One of the ways in which energy may be transferred between stores without transferring matter

  
• Oscillations


  Repeated and regular fluctuations above and below a fixed point
• Vibrations


  Repeated forwards and backwards movement about a fixed point
• Longitudinal wave


  A wave in which the vibrations or oscillations are parallel to the direction of wave travel

  
• Compression


  A region in a longitudinal wave where the particles are closest together

  
• Rarefaction


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

  
• Examples of longitudinal waves

  Sound, ultrasound, seismic P-waves
• Transverse wave


  A wave in which the vibrations or oscillations are perpendicular to the direction of wave travel

  
• Examples of transverse waves

  Water waves, vibrations along a string, Mexican wave, electromagnetic waves (light waves, microwaves, radio waves etc), seismic S-waves
• Mechanical waves


  Cause the particles in a solid, liquid or gas to oscillate and need medium to travel through

  
• Electromagnetic waves


  Cause electrical and magnetic fields to oscillate

  
• Rest position


  The position of particles or fields when they are not vibrating

  
• Displacement


  The distance that a point of a wave has moved from its rest position
• Amplitude (a)


  The maximum displacement of a point of a wave from its rest position

  
• Peak or crest


  The largest displacement of a point of a wave above the rest position

  
• Trough


  The largest displacement of a point of a wave below the rest position

  
• Wavelength (λ)


  The distance covered by a full cycle of the wave