1. Reflection When a wave comes to the end of the medium it is traveling in, it is partially reflected back.

2. Refraction When a wave crosses a boundary between mediums and its velocity changes as a result, the transmitted wave may move in a different direction than the incident wave (“bent”).

3. Diffraction Process of waves bending around obstacles

4. Interference When two waves pass through the same region of space at the same time. The resultant displacement is always the sum of the separate (component) displacements.

5. Add Together Cancel Each Other Out Constructive Interference: Add Together Destructive Interference: Cancel Each Other Out

6. Constructive vs. Destructive Two Waves in Phase Two Waves 180° Out of Phase Combined Waveform Wave 1 Wave 2