Waves

Waves

1. Types of Waves

   • Longitudinal
     • Vibrations parallel to direction of energy transfer
     • Compressions and rarefactions
   • Transverse
     • Vibrations Perpendicular to the directions of energy transfer
     • Light or any other electromagnetic wave
     • Peaks and troughs
   • Sound waves

2. Equations

   • Time Period = 1/frequency
   • wave speed = frequency x wavelength

3. Sound

   • Ears
     • Outer ear channels sound down the ear canal
       • Hits ear drum where it is pushed in in compressions and out in rarefactions
         • Vibrations transfer to fluid in inner ear
           • Small hairs move with fluid which is converted into sound
     • Only above 20Hz and below 20kHz
       • Above 20 kHz is ultra sound
         • Used to calculate water depth and to see inside human body
       • Below 20Hz is infrasound
         • Seismic waves
           • P waves = First and travel longitudinally through water and solid
           • S waves = Second and travel transversely through just solids

4. Electromagnetic spectrum

   • Radio---Micro---Infrared---Visible light---Ultraviolet---X-ray---Gamma
     • High Frequency
       • High Energy
       • Short Wavelength
   • Long wavelength
     • Low Frequency
     • Low Energy
   • Dangers
     • IR-Burns
     • Visible Light- eye damage
     • UV-retina damage and skin cancer
     • X-ray and gamma ray-cancer causing

5. Refractions

   • Enter denser material bends away from the normal

6. Light Colour

   • Primary Colours - RED, GREEN, BLUE
   • RED+BLUE=Magenta
   • BLUE+GREEN=Cyan
   • RED+GREEN=Yellow