Waves

Waves

1. Electro-Magnetic

   • Sprectrum
     • Radio--Microwaves-Infrared-visible light-ultraviolet-xrays-gamma
       • Low Frequency
         • Low energy
           • High wavelength
       • High frequency
         • High energy
           • Low Wavelength
   • Dangers
     • Infrared-Burns
     • Visible Light- Eye issues
     • UV - retina damage, sunburn, skin cancer
     • Gamma, X-rays - Cancer
   • Uses
     • Radio - Communication
     • Micro - Heating food, satellite communication
     • Infrared
       • Cooking Food
     • Visible Light - Sight, fibre-optic cables
     • UV - Tanning beds, security tags
     • X-rays
       • Medical Imaging
     • Gamma
       • Sterilisation
       • Radiotherapy
   • Light- colour
     • Red
     • Green
       • Yellow
     • Blue
       • Teal
       • Magenta
     • Filters only allow light of a certain wavelength to pass through
     • Objects appear a colour as that is the range of wavelengths that it does not absorb

2. Seismic

   • P-waves
     • Faster
     • Solids and Liquids
   • Slower
   • Just Solids

3. Definitions

   • Transverse - Motion of Particles is perpendicular to direction of energy transfer
   • Longitudinal - Motion of Particles is paralell to direction of energy transfer

4. Practicals

5. Sound

   • Ultrasound = 20kHz and above - medical imaging and depth in oceans
   • Humans = 20Hz-20kHz