## Constructive and destructive wave

constructive wave :

A constructive wave id when two crests from opposite directions converge and the end result wave is the sum of the two crests.

destructive wave :

A destructive wave is when a crest and a troph from opposite directions converge.  the end result wave usually cancels out (no wave) or they act against each other.

How do noise-cancelling headphones use wave interference to eliminate unwanted sound?

A : The music going into the ear acts as a constructive wave.  Another wave is created through the headphones that acts as the troph with the same amplitude, and the background noise acts as the crest that creates a destructive wave that cancels out any noise.

## Types of waves

Pulse wave: A pulse wave is a non-repeating wave; single disturbance.

Pulse wave

Periodic : Periodic waves are waves that repeat at regular intervals.  they require regularly repeating disturbances in order to be considered a periodic wave.

Periodic wave

Longitudinal:  A longitudinal wave is when several turns of the spring are compressed and released.  The disturbance is in the same direction as the direction of travel.  This wave occurs lengthwise.

Longitudinal wave

Transverse: This wave occurs sideways.  The spring is pulled sideways at a 90 degree angle (right angle) then released.  The wave will travel across instead of lengthwise.

Transverse wave