1. Wave Behavior
Unit 7 –Lecture 3

2. Clarity Substances have varying levels of clarity –
transparent materials allow waves to pass through with minimum or no distortion

3. Clarity Substances have varying levels of clarity –
translucent materials allow waves to pass through them with varying degrees of distortion

4. Clarity Substances have varying levels of clarity –
opaque materials do not allow waves to pass through them
waves must be reflected or absorbed

5. Reflection occurs when a wave strikes an object and bounces off of it
echos (& echolocation)
image in mirror

6. Reflection Law of Reflection
the angle of incidence [input] must equal the angle of reflection [output]

7. Smooth Surface Rough Surface
Mirrors
mirrors must be smooth so all the angles line up to make a clear picture in the reflection [plan(e/ar)]
Smooth Surface Rough Surface

8. Mirrors Concave “caved in” light rays, etc., converge in the center
make the image larger or focus energy

9. Mirrors
Parabolic
Satellite dishes
Lighting the Olympic Torch

10. Mirrors Convex “curved out”
Light rays, etc., spread out from the center
Images look smaller, but cover more area

11. Mirrors

12. Refraction bending of a wave as it moves from one medium to another
the image difference is caused by a change in the speed of the wave

13. Refraction
“edges” of wave “slow down” in a more dense medium and “speed up” in a less dense medium
bends towards the “normal” in a more dense medium
away from the “normal” in a less dense medium

14. Refraction depends on the type of medium
the angle the wave hits the medium
waves of light move faster through air than through water

15. Refraction
Law of Refraction

16. Refraction Oil & Gasoline Rainbows
because of the different densities of oil, gasoline, water, and air, a rainbow- like refraction can form in puddles near well- traveled parking lots

17. Refraction
Lenses act to control the refraction of light to focus it in a more desirable manner.

18. Diffraction the bending of waves around a barrier
if 1 edge, only one curve
if 2 edges, both will bend the wave

19. Diffraction

20. Interference caused by the passing of two waves through one another
how the waves line up determines how they will interact

21. Interference constructive interference – crests and troughs line up
build on one another
are said to be “in phase”

22. Interference destructive interference –
crests and troughs don’t line up
lessen one another
said to be “out of phase”
if they are exactly opposite, they will cancel each other out

23. Interference

25. Homework FINISH YOUR WAVES PACKET complete worksheet on back of notes
We will be going over it on Monday.
complete worksheet on back of notes
study for upcoming test = Weds next week