refraction

• What is the effect called when light waves change direction at a boundary?

  Refraction
• What happens to light waves when they pass from air to glass?

  They change speed and direction
• What occurs when light enters a denser substance?

  It slows down and bends towards the normal
• What happens when light moves into a less dense substance?

  It speeds up and bends away from the normal
• How are angles measured in refraction diagrams?

  • All angles are measured from the normal
  • The normal is a line at 90° to the surface
• Why do some objects appear to bend when viewed through water?

  Due to the effect of refraction
• What is the angle of incidence?

  The angle the incident ray hits the block
• What is the angle of refraction?

  The angle the refracted ray travels
• What happens to light as it enters a glass block from air?

  It changes direction towards the normal
• What is the speed of light in air or a vacuum?

  Approximately $300,000,000 \text{ m/s}$
• What is the speed of light in glass?

  Around $200,000,000 \text{ m/s}$
• Why does light bend when entering glass?

  One side enters first and slows down
• What analogy is used to explain light refraction?

  A car moving from tarmac to mud
• What is a convex lens and its function?

  • A lens that bulges outwards
  • Focuses light rays to a single point
  • Important for clear images in eyes and photographs
• What is the purpose of focusing light?

  To get clear images
• Where are convex lenses commonly found?

  • Magnifying glasses
  • Spectacles for long-sight
  • Telescopes
  • Cameras
• How does the eye use a convex lens?

  It changes shape to focus images
• What are the main parts of the eye involved in vision?

  Iris, pupil, retina, lens, optic nerve
• what are the 2 types of refraction?

  natural and artificial
• there are two types of refraction