Light

Light

1. Reflection

   • the image in a plane mirror is...
     • virtual
     • the same size as the object
     • laterally inverted
     • the same distance behind the mirror as the object is in front of the mirror

2. Refraction

   • happens when a beam of light passes from one material into another, due to a change in its speed
   • a ray parallel to the normal does not refract
   • light bends towards the normal when it slows down and away from the normal when it speeds up (TAGAGA/TAWAWA/TAPAPA)

3. Dispersion

   • Different colours (or frequencies) of light travel at different speeds in glass
     • when light is passes through a prism (a triangular glass block), a spectrum is produced
     • violet light is slowest, red light is fastest

4. Total Internal Reflection

   • In any glass block, some light is internally reflected
     • when the emerging ray on the other side comes out along the surface, most of the light is internally reflected
       • the angle where the emerging ray lies along the surface is called the critical angle
         • after this all light is internally reflected

Images and files in the map