Waves and heat

• Wave


  A method of transferring energy from one place to another through vibrations
• Wave types


  • Transverse waves
  • Longitudinal waves
• Transverse waves


  • Particles in the medium vibrate perpendicular to the direction of the wave
• Longitudinal waves


  • Particles in the medium vibrate parallel to the direction of the wave
• Transverse waves


  • Light
  • Infrared
  • Water
• Longitudinal waves


  • Sound
  • Ultrasound
• Wavelength


  The distance between two consecutive crests or troughs
• Amplitude


  The maximum displacement from the rest position
• Frequency


  The number of waves produced per second, measured in Hertz (Hz)
• Wave equation


  1. v = fλ

  2. Wave speed (v) is measured in m/s

  3. Frequency (f) is measured in Hz

  4. Wavelength (λ) is measured in m
• Prefixes

  • G (x10^9)
  • M (x10^6)
  • k (x10^3)
  • c (x10^-2)
  • m (x10^-3)
• Regions of the electromagnetic spectrum


  • Radio
  • Microwave
  • Infrared
  • Visible light
  • Ultraviolet
  • X-ray
  • Gamma
• The electromagnetic spectrum is a continuous series of waves of varying wavelengths and frequencies
• Increasing wavelength


  Decreasing frequency
• Increasing frequency


  Decreasing wavelength
• All parts of the electromagnetic spectrum can travel through a vacuum, travel at the speed of 3x10^8mph , all transverse waves
• Uses of different regions of the electromagnetic spectrum


  • Radio - communications
  • Microwave - heating, mobile phones
  • Infrared - remote control
  • Visible light - photography
  • Ultraviolet - detecting forgeries, sunbeds
  • X-ray - detecting broken bones, sterilising medical equipment
  • Gamma - cancer treatment
• Dangers of EM waves 


  Infrared-Burns

  visible light - potential damage to eyes

  ultra-violet- skin cancer

  xray and gamma - lead to cancer and damages cells
• Gamma rays have a higher fee therefore more waves coming per second therefore they have more energy hence are more dangerous to humans