Light (Chapter 5)

• Properties of light

  -Light is a form of energy.

  -Light always travels along a straight line.

  -Light travels at a speed of 3 x 10^8m/s in a vacuum

  -Light can be reflected/refracted
• Reflection of light

  -Bounces off light rays of a surface

  -Laws of reflection of light

  ~Incident ray, reflected ray and normal must lie on the same plane

  ~Angle of incidence=Angle of reflection
• Characteristics of image formed in a plane mirror

  1. Virtual
  2. Same size as object
  3. Laterally inverted
  4. Upright
  5. Same distance as the object from the mirror
• Refraction

  -Refraction is the change in direction of the light ray passing from one medium to another caused by its change in speed

  -Laws of refraction

  ~Incident ray, reflected ray and normal must lie on the same plane

  ~Sin i/Sin r = Formula of refractive index