1. Interference of WAves (9.1)
The process of generating a new wave when two or more waves meet is called interference.

2. Terminology
Two waves are said to be “In Phase” when their crests and troughs meet at the same place and same time thus creating constructive interference.
Two waves are said to be “Out of Phase” when the crest of one wave meets the trough of the second wave at the same time thus creating destructive interference.

3. Terminology

4. Principle of Superposition
The Principle of Superposition states that at any point the amplitude of two interfering waves is the simply the sum of the amplitudes of each individual wave

5. Types of Interference Constructive Destructive
The process of forming a wave with a larger amplitude when two or more waves combine
The process of forming a wave with a smaller amplitude when two or more waves combine

6. Types of Interference

9. Interference of Waves Simulator

10. Technology Using Interference of Waves
Noise Cancelling Headphones
Use concept of destructive interference to cancel out unwanted noise so we can listen to music at a lower volume
Image taken from pg. 418 of Nelson Physics 11

11. References https://www.youtube.com/watch?v=x2Iwrhynq9o
Nelson Physics 11