Reflections in Plane Mirrors.docx

  • Reflections in Plane Mirrors
  • Learning Expectation(s): A1.12, A2.2, E2.1, E2.2
  • Plane Mirror Terminology
  • mirrors were invented by German chemist Justus von Leibig
  • plane mirror: flat reflective surface
  • incident ray: ray of light that travels to mirror; must:
  • be a solid, straight line
  • have an arrowhead
  • touch the mirror surface
  • normal: line perpendicular to mirror where incident ray hits; must:
  • be a dashed, straight line
  • touch the mirror surface
  • reflected ray: ray of light that travels away from mirror; must:
  • be a solid, straight line
  • have an arrowhead
  • touch the mirror surface where incident ray hits
  • Law of Reflection
  • described by ancient Greek mathematician Euclid
  • the angle of incidence is always equal to the angle of reflection
  • angle of incidence ( ⦨ i ): angle between incident ray and normal
  • angle of reflection (⦨ r ): angle between reflected ray and normal