When two waves interfere, the resulting amplitude and phase at any point in time depend on the relative phase and amplitude of the two waves. There are two main types of interference: constructive and destructive.
- Constructive Interference: In constructive interference, the waves are in phase with each other, meaning their peaks and troughs align. When two waves interfere constructively, their amplitudes add up, resulting in a larger combined amplitude at the point of interference. The resulting amplitude is the sum of the individual amplitudes of the waves.
The phase of the combined wave remains the same as the original waves. If both waves have the same phase, the resulting wave will also have the same phase as the original waves.
- Destructive Interference: In destructive interference, the waves are out of phase with each other, meaning their peaks and troughs are misaligned. When two waves interfere destructively, their amplitudes partially or completely cancel out at the point of interference.
If two waves have equal amplitudes but are 180 degrees (π radians) out of phase, they will completely cancel each other, resulting in zero amplitude at the point of interference.
The phase of the combined wave depends on the phase relationship between the original waves. If the original waves are out of phase, the resulting wave will have a phase shift compared to the original waves. The specific phase shift depends on the phase difference between the waves.
It's important to note that interference patterns can be more complex when considering multiple interfering waves or when the waves have different frequencies, directions, or polarizations. The resulting amplitudes and phases at any point in time are determined by the specific conditions and interference phenomena involved.