Wave Interactions

Reflection

The bouncing back of a wave when it meets a surface or boundary.

Diffraction

The bending of a wave as it passes an edge or an opening.

This is why you can hear sound around a corner.

Refraction

The bending of waves as they pass from one medium to another.

“Broken pencil” trick

Interference

Waves that exist in the same place at the same time experience interference.

Interference

Constructive: Two crests or two troughs will add together to make a larger crest or trough. They do not average out.

Destructive: Crest meets trough; amplitude is smaller or completely cancels out.

Interference

Of light: creates rainbows in oil or soap bubbles.

Of sound: creates beats in music.

The Doppler Effect

The apparent change in frequency of a moving object to the observer.

Ex: NASCAR, ambulance