A Level Physics Practice Exam

What term describes two points that are the same side of the rest position on a stationary wave?

1. Out of phase

2. In phase

3. Phase-shifted

4. Mixed phase

The correct answer is: In phase

The term that describes two points that are on the same side of the rest position in a stationary wave is "in phase." This means that both points oscillate together, reaching their maximum and minimum displacements simultaneously. In a stationary wave, points that are in phase are characterized by having the same displacement from the equilibrium position at the same time; they move together, whether both are at a peak (crest) or a trough. This concept is crucial in understanding wave interactions, as in-phase points can constructively interfere, leading to points of maximum amplitude along the wave. On the other hand, the term "out of phase" refers to points that are on opposite sides of the rest position, meaning they reach their maximum and minimum displacements at different times, which could lead to destructive interference. "Phase-shifted" describes a more general relationship where one wave lags or leads another, but it does not specifically indicate being on the same side of the rest position. "Mixed phase" is not a standard term used in the context of wave behavior to describe stationary waves. Therefore, "in phase" accurately captures the relationship between points on the same side of the rest position.