Reflection and refraction

Reflection and refraction

1. Reflection

   • When the wave can bounce back. e.g. light hitting a mirror
   • This occurs when a wave travelling in one direction strikes the surface of a different medium and changes direction so that it returns back into the direction in which it was originally travelling in.
   • When waves undergo reflection the angle the incoming waves make with the surface is equal to the angle of the reflected waves. This is the Law of Reflection and can be written as; The angle of incidence = the angle of reflection

2. Refraction

   • The wave can change speed and direction e.g. light travelling from air into water
   • The speed at which a wave travels is dependant upon the medium in which it travels along or through.
   • The speed of a wave changes when a wave moves from one medium to another. This change in wave speed is accompanied by a change in wavelength and change in direction. It is this change of direction or bending of the wave as it passes from one medium to another that is called refraction.