Light

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Created by: Meg Bernardo
Created on: 08-07-14 14:36

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Light
- Reflection
  - Laws
    - The incident ray, the reflected ray and the normal to the surface all lie in the same plane.
    - The angle of incidence is equal to the angle of reflection.
  - Types
    - Regular
      - light reflected in 1 direction
      - occ on smooth surfaces
      - clear images formed
    - Diffused
      - No clear image
- Images in a plane mirror
  - same size as the obj
  - Laterally inverted
  - upright
  - virtual
  - @ a position as far behind the mirror as obj is in front of mirror
- Other mirrors
  - Convex
    - provides wider field of vision
    - images small, distorted
    - uses
      - placed ard road bends
      - in stores
    - ie surface curves outwards
  - Concave
    - magnify images
    - ie surface curves inwards
- Refraction
  - Definition
    - Bending of light as it enters a different medium at an angle
      - occurs due to change in speeds of light in the two media.
        Speed of light < as it travels through a denser medium.
        rarer --> denser medium
        bends towards normal
        
        optically denser material is one that bends light more
      - How?
        rarer --> denser medium
        bends towards normal
        
        denser --> rarer medium
        bends away fr normal
  - Examples
    - Glass blocks
    - Swimming pool
      - Real and apparent depth
  - Dispersion
    - ie splitting of light into spectrum of its component colours
      - White liight is m/u of 7 colours (roygbiv, in order of longest to shortest wavelength)
        violet -- travels slowest, so refracted most
        
        red -- travels fastest, so refracted least
      - How?