When two equal amplitude sound waves interfere destructively, the phase difference between them is 180 degrees or π radians.
In the context of waves, the phase represents the position of a wave cycle at a particular point in time. The phase difference between two waves determines how they align or misalign with each other. Destructive interference occurs when the crests of one wave coincide with the troughs of the other wave, resulting in cancellation and a reduction in overall amplitude.
A phase difference of 180 degrees means that when one wave is at its peak (crest), the other wave is at its lowest point (trough), or vice versa. This alignment creates destructive interference, causing the waves to partially or completely cancel each other out.
It's important to note that destructive interference occurs when the waves have the same frequency and amplitude but are out of phase by 180 degrees. If the phase difference is not exactly 180 degrees, the interference may be partial, resulting in a reduction in amplitude but not complete cancellation.