wave reflection and refraction

• all waves can be...

  absorbed, transmitted or reflected
• wave absorption


  when a wave is absorbed by the material it is trying to cross into, energy is transferred to the material's energy stores
• wave transmission


  when a wave is transmitted, the waves carry on travelling through the new material, often leading to refraction
• wave reflection


  when a wave is reflected, it rebounds off the surface of the material it hits
• angle of incidence =

  angle of reflection
• angle of incidence


  the angle between the incident ray and the normal
• ray of incidence


  original beam of light that reflects on the surface
• angle of reflection


  the angle between the reflected ray and the normal
• ray of reflection


  beam that comes away from the reflected surface
• normal line


  imaginary line drawn perpendicular to the surface of a mirror or any surface
• reflection ray diagram

  
• reflection can be...


  specular or diffuse
• specular reflection


  happens when a wave is reflected in a single direction by a smooth surface (e.g. a mirror) and gives a produces reflection
• diffuse reflection


  when a wave is reflected by a rough surface (e.g. paper) and rays are scattered in lots of different directions, giving no clear reflection
• refraction


  the bending of a wave as it passes at an angle from one medium to another
• how much a wave is refracted depends on...

  how much the wave speeds up or slows down, which usually depends on material density
• materials with high density ... waves passing through it

  slows down
• materials with low density ... waves passing through it

  speeds up
• if a wave crosses a boundary and slows down, it will bend ... the normal


  towards
• if a wave crosses a boundary and speeds up, it will bend ... from the normal


  away
• the ... of a wave changes when a wave is refracted

  wavelength and amplitude
• the ... of a wave doesn't change when a wave is refracted

  frequency
• a wave traveling perpendicular to a boundary of another medium will...

  not refract
• a wave meeting the boundary of another medium as an angle will...

  refract
• optical density


  measures how well a medium can transmit light
• higher optical density means light waves travel ... through it

  slower
• lower optical density means light waves travel ... through it

  faster
• refraction diagram