WAVES

WAVES

1. waves have amplitude, wavelength and frequency

   • amplitude is the waves' depth on the diagram - from the middle line to the bottom of the trough(curve)
   • Wavelength is distance from any point on a wave and same point on next wave.
   • Frequency is number of complete waves passing a certain point per second (Hz) 1 Hz = 1 wave/second
   • Wave speed
     • Wave speed(M/S) = Frequency (Hz) * Wavelength (M)

2. Transverse waves

   • Vibrate with displacement perpendicular to direction of travel - SIDEWAYS vibrations
     • E.G of transverse waves = Light waves, all EM waves, ripples on water, waves on string and a slinky being wiggled up and down

3. waves transmit energy from one place to another either through space or material

4. Longitudinal waves

   • vibrate with a displacement parallel to direction of travel of wave, it contains areas of compressions and rarefactions - Vibrations along the SAME LINE
     • E.g of longitudinal waves = sound + ultrasound waves, shock waves(seismic waves), slinky spring when you push or pull the end
       • When sound travels through air, particles vibrate backwards and forwards parallel to direction of wave

5. WAVE PROPERTIES

   • All wave can be reflected, refracted and diffracted
     • When waves arrive at an obstacle or meet a new material their direction of travel can change
       • Which can happen by reflection, refraction or diffraction
         • Reflection of light allows us to see things
           • Reflection of light lets us see things, light bounces off objects into our eyes
             • If light travelling in the same direction reflects from an uneven surface(E.G paper) the light reflects off at different angles.
               • If light travelling in the same direction reflets from an even surface(smooth and shiny) E.G mirror then its all reflected at same angle and it's a clear reflection
                 • Law of reflection is ANGLE OF INCIDENCE = ANGLE OF REFLECTION
                   • These two angles are always defined between the ray itself and normal not between ray and surface!
           • Mirrors
             • The image is same size as the object
               • Image is virtual and upright because object appears to be behind mirror
             • As far behind mirror as object is in front
               • The image is laterally inverted (left and right sides are swapped) - basically the objects left side becomes its right side