A phase difference in stationary waves refers to the difference in the position of two waves that have the same frequency and amplitude but are out of phase with each other. In other words, it is the difference in the starting point of the wave cycle between two waves.
Phase difference is measured in degrees or radians, with a full cycle being 360 degrees or 2π radians. The phase difference can also be expressed as a fraction of a cycle, such as 1/4 or 3/4 of a cycle.
The phase difference in stationary waves is important because it determines the interference pattern between the waves. When two waves with the same frequency and amplitude have a phase difference of 0 degrees, they will constructively interfere and create a larger amplitude. However, when the phase difference is 180 degrees, the waves will destructively interfere and cancel each other out.
The phase difference between two waves does not affect the wavelength of the waves. The wavelength is determined by the source of the waves and remains the same regardless of the phase difference.
Phase difference is closely related to standing waves because standing waves are created by the interference of two waves with the same frequency and amplitude, but traveling in opposite directions. The phase difference between the two waves determines the nodes and antinodes in the standing wave pattern.