In human society, one thing is almost always present: conflict. In the world of sound and waves, there is also conflict. However, this type of conflict is different: it is the collision of two waves. As you might imagine, when two waves collide with each other, a bigger wave should be created. Imagine yourself with a friend shoveling a snow. You agree to shove all the snow into the middle of you r driveway. As you shovel snow towards the driveway, the pile of shoveled snow increases in size. When two waves collide and produce a new wave, it is called wave interference. There are two types of wave interference: constructive and destructive.
During any wave interference the shape of the medium is determined by the sum of the separate amplitudes of each wave. We often say that when waves interfere, amplitudes add.
Constructive Interference
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| Constructive Interference |
When the crest of one wave passes through the crest of another wave, we say that the waves constructively interfere. Constructive interference also occurs when the trough of
one wave passes though the trough of another wave.
During any wave interference the shape of the medium is determined by the sum of the separate amplitudes of each wave. We often say that when waves interfere, amplitudes add.
Destructive Interference
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| Destructive Interference |
During any wave interference the shape of the medium is determined by the sum of the separate amplitudes of each wave. We often say that when waves interfere, amplitudes add. During destructive interference, since the positive amplitudes from one crest are added to the negative amplitudes from the other trough, this addition can look like a subtraction.
