A level revision

Superposition

Superposition occurs when two or more waves meet, a simple example:

It looks like nothing happened, in actual fact at the very instant the waves passed one another their displacements combined, cancelling out, leaving no wave at all before carrying on their way again. In general the principle of superposition is that:

The total displacement at a point equals the sum of the individual displacements at that point.

The 3 basic rules you need to remember:

• peak + peak = 'superpeak'
• trough + trough = 'supertrough'
• peak + trough = no displacement