When two waves moving through a medium meet with each other at a particular point in space at the same time, they interact with each other by combining and forming a net wave. The amplitude of this new net wave is equal to the vector sum of all the wave amplitudes that come together at that specific point. This phenomenon is called
interference and it is governed by the
principle of superposition (the concept of the sum of all amplitudes).
There are two types of wave interference: constructive and destructive. Constructive wave interference occurs when two waves meet and cause an amplification of the amplitude in the resultant. Destructive interference is the opposite, occurring when two waves meet and cause a decrease in the amplitude in the resultant. (see diagram below)
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| Constructive vs. destructive wave interference. |
