1. Refraction -Refraction of Sound -Refraction of Light

2. Is it harder to push a lawn-mower on concrete or grass? Is it harder to walk through a pool full of water or air? Do you think that light waves also have a harder time going through water than air? Refraction

3. The change in direction of a wave as it crosses the boundary between two media in which the wave travels at different speeds. Both light and sound waves change direction when they enter new media at angles greater than 0 o.

4. Refraction of Sound Sound waves are refracted when parts of a wave front travel at different speeds. Do sound waves travel faster in warmer or colder air?

5. Refraction of Sound

6. Refraction of Light

7. Light changes speed as it passes from one medium to another. This changes the directions of light rays.

8. Refraction of Light When light rays enter a medium in which their speed decreases, the rays bend toward the normal. When light rays enter a medium in which their speed increases, the rays bend away from the normal.

9. Index of Refraction and Snell’s Law Index of Refraction: Snell’s Law: n = speed of light in vacuum speed of light in material n sin = n’ sin ‘