Reflection and refraction

• The law of reflection states the angle of incidence equals the angle of reflection.
• Refraction is where a wave changes direction at a boundary due to a change in speed of the wave from one medium to another. When light speeds up at a boundary , it refracts away from the normal .
• When light changes from a less dense medium to a more dense medium its speed decreases but its frequency stays the same. hence wavelength also decreases .
• Refractive index is the ratio of a waves speed in a vacuum to its speed in a medium.
• to find refractive index where you have angle of incidence and angle of refractions you use;

  • n= sin (i)/ sin (r)