1. All of these behaviors occur with mechanical and electromagnetic waves
Wave behaviors
Interference Doppler Effect
Reflection
Refraction Diffraction
All of these behaviors occur with mechanical and electromagnetic waves

2. Interference of Waves
When waves arrive at the same place at the same time, interference occurs as they interact =

3. Constructive interference (superposition)
- When identical parts of a wave overlap Ex: crest/crest, compression/compression
Build on each other (increase amplitude)
Also called reinforcement or In Phase

4. Destructive interference
-When opposite parts of a wave overlap Ex: crest/trough, compression/rarefaction
Cancel each other out (decrease amplitude)
Also called out of phase

5. Effect of superposition
Beats – effect that results when 2 tones of slightly different frequencies are sounded together.
Some overlap (louder) and some cancel (softer) beats
Unknown frequency activity

6. Resonance – when the frequency of a forced vibration on an object matches the natural frequency of that object.
Matching the rhythm (frequency) can amplify vibrations
Shattering glass
(rock star)
(little kid)

7. Doppler effect
Doppler Effect – The change in frequency of a wave due to the motion of the wave source or wave receiver
Ex. Sound of a train approaching
Increase in frequency as it approaches
Decrease in frequency as it moves away

8. Doppler effect videos interactive view of waves moving sound source
moving plane

9. Behavior of Waves
When waves interact with a boundary, it can change the speed and/or direction of a wave. A boundary is the transition point between two different mediums (air/water, cold air/warm air, air/table)

10. Reflection Reflection – when a wave bounces off an object/boundary
Incident ray- incoming ray
Reflected ray- outgoing ray
Normal- imaginary perpendicular to the reflective surface
Law of reflection- angle of incidence = angle of reflection

11. Refraction
Refraction – when a wave bends due to a change in speed as it passes between two different boundaries
Index of refraction- determines the amount of bending of the wave as it passes from one medium to another

13. Diffraction
Diffraction – the spreading of a wave as it moves through an opening or around an object