Waves

Waves

1. A wave is an oscillation accompanied by a transfer of energy but not matter.

   • Longitudinal Waves
     • vibrations travel parallel to the direction of the wave
   • Transverse Waves
     • vibrations travel perpendicular to the direction of the wave
   • Wave Diagrams
     • Amplitude- the max. disturbance from the rest position. The higher the amplitude, the higher the energy.
     • Wavelength- the distance of one complete wave.
     • Time Period- time taken for one complete wave to pass a point.
     • Frequency- number of waves propagated per second. measured in Hertz.
   • Electromagnetic Spectrum
     • It is the range of wavelengths or frequencies over which electromagnetic radiation extends.
       • All are transverse and travel at the speed of light. They can be reflected, refracted and diffracted.
     • Radio Waves
       • Microwaves
         • Infrared
           • Visible Light
             • Ultraviolet
               • X-rays
                 • Gamma Rays
   • Wave Speed= Frequency x Wavelength
   • Sound Waves
     • The Doppler Effect- When a siren moves towards a person, it sounds higher pitched because sound waves become squished and have a higher frequency. When it moves away from a person, it sounds lower pitched as the waves expand and have a lower frequency.
   • Reflection
     • Properties- virtual, upright, left-right reversed, the same distance from the mirror as the object's distance, and the same size as the object.
   • Refraction
     • Happens when a wave goes from one medium to another and changes speed and direction
       • n= sin i / sin r
   • Total Internal Reflection
     • complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium. The phenomenon occurs if the angle of incidence is greater than a certain limiting angle, called the critical angle.

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