1. Section 3: Interactions of Waves
Do Now: With your teammates – review HL#4
RR: Share any questions your teammates have
Cornell Notes: 12/3/15
- FQ What causes waves to change directions?

2. Reflection (Station 1)
When an object or a wave hits a surface through which it cannot pass, it bounces back, or reflects
Ball hitting a wall
Light in the mirror
Echoes
Water hitting barrier

3. Reflection Vocabulary
Incident wave or Incoming wave
Reflected wave
Normal line or Perpendicular line
Angle of incidence
Angle of reflection
The Law of Reflection states that the angle of incidence equals the angle of reflection

4. Reflection
How can we use the Law of Reflection to play a game of pool (billiards)?
Draw a sketch of reflection on a pool table…and discuss it with your partner. I want to see ANGLES!!!!!!
Follow-up Question: Explain the strategies you used to play virtual pool and relate them to the law of reflection.

5. Refraction

6. Refraction (Station 3)
Def.: When a wave enters a new medium at an angle, one side of the wave changes speed before the other side, causing the wave to bend
This bending only occurs when the wave enters the medium at an angle

7. Diffraction (Station 6)
When a wave moves around a barrier or through an opening in a barrier, it bends and spreads out, or diffracts.
This behavior indicates that light travels in waves….

8. Interference The interaction between waves that meet Constructive
Destructive

9. Standing Waves
If two waves coming from opposite directions have just the right frequency, they produce a combined wave that appears to be standing still
Standing wave – a wave that appears to stand in one place even though it is really 2 waves interfering as they pass through each other
Nodes – points of zero amplitude, always evenly spaced
Antinodes – points of maximum amplitude & maximum energy
Standing waves video on YouTube

10. Resonance Resonance Video Breaking Glass with Sound
An increase in the amplitude of a vibration that occurs when external vibrations match an object’s natural frequency
When do you push someone on a swing?
Resonance Video
Breaking Glass with Sound
Tacoma Narrows Bridge Collapse