1. Reflection & Refraction
Chapter 29

2. Reflection
When a wave reaches a boundary between two media and waves bounce back into the first medium
Examples: Mirrors, shiny metal

3. Law of Reflection
Angle of incidence for a wave that strikes a surface is equal to the angle of reflection
True for all waves (sound=echo, light, etc.)
Normal

4. Opaque Transparent Translucent
Materials that absorb light without reemission and do not allow light to pass through
Transparent
Materials that allow light to pass through them in straight lines
Translucent
Material that allows light to pass through but not detailed images (semitransparent)

5. Refraction
Change in direction of a wave as it crosses the boundary between two media in which the wave travels at different speeds
Example: light traveling through air then water

6. Snell’s Law
The relationship between the angles of incidence and refraction and the indices of refraction of the two media

7. If light enters a medium in which the speed decreases, (air to water), the rays bend toward the normal
If light enters a medium in which the speed increases, the rays bend away from the normal