refraction

• what is the refraction of light waves?

  when waves change direction as they pass from 1 medium to another (e.g. air into glass)
• waves travel at different ______ in different materials (mediums)

  speeds
• why do waves travel at different speeds in different mediums?

  because different materials (mediums) are different densities
• for electromagnetic waves, like light, the higher the density of the material, the ______ the wave will travel through it

  slower
• what will happen to a wave as it travels from a less dense medium (air) to a more dense medium (glass)


  it will slow down
• what will happen if the wave is travelling perpendicular to the two boundaries of the mediums?


  it will just continue straight on
• what will happen is the wave hits the medium at an angle?

  it will be refracted, this means its direction will change
• what happens if a refracted wave is passing into a more dense medium?

  it will bend towards the normal
• what happens when the refracted ray is passing from the more dense glass to the less dense air?

  it will bend away from the normal. this is called the emergent ray.
• what happens to the wavelength and frequency as the speed of the wave changes while passing from one medium to another?


  the wavelength changes while the frequency always stays the same
• if the speed of a wave increases the wavelength must ________ as well


  increase
• different wavelengths are _________ by different amounts

  refracted
• what happens if we put a white light (containing all the wavelengths/colours of visible light) through a triangular prism?


  the different colours will bend to different degrees so they will all spread out like a rainbow