Waves Interference for AP Physics B & C

Practice problems for these concepts can be found at:

Waves Practice Problems for AP Physics B & C

When two waves cross each other's path, they interact with each other. There are two ways they can do this—one is called constructive interference, and the other is called destructive interference.

Constructive interference happens when the peaks of one wave align with the peaks of the other wave. So if we send two wave pulses toward each other as shown in Figure 23.6a, then when they meet in the middle of the string they will interfere constructively (Figure 23.6b).

The two waves will then continue on their ways (Figure 23.6c).

However, if the peaks of one wave align with the troughs of the other wave, we get destructive interference. For example, if we send the two wave pulses in Figure 23.7a toward each other they will interfere destructively (Figure 23.7b), and then they will continue along their ways (Figure 23.7c).

Practice problems for these concepts can be found at:

Waves Practice Problems for AP Physics B & C