1. Wave Interactions

2. Reflection – Bounce back wave
Sound waves that are reflected are called echoes
Used in sonar and echolocation
How wave is reflected depends on if the end if “fixed” or free
Opposite wave reflected
Same side wave

3. Refraction
The bending of a wave due to the wave moving from one type of medium into another.
Caused by change in wave speed through the new medium

4. Diffraction
Wave passing a barrier or going through a hole in a barrier bends causes the wave to wrap around the barrier
ex) Hearing music playing but not knowing where it’s coming from or hearing sounds under water

5. Interference
When two or more waves meet, they interact. This is called interference.
1. Constructive Interference – the combining of waves to cause higher amplitude of any of the original waves.
2. Destructive Interference – when the combining of the waves produce a new wave with a smaller amplitude than the beginning waves

6. Constructive Interference
Waves with same amplitude meet
Adds together to make a greater amplitude

7. Destructive Interference
Waves with opposite amplitudes meet
Waves meet and create smaller waves
Wave keep moving along medium

9. Standing Waves
Standing Waves – the combining of the incoming and reflected wave so that the resultant wave appears to be standing still
Node – the point where Constructive Interference and Destructive Interference cause an amplitude of zero on the standing wave (no motion).