A Level Physics Practice Exam

Two points on a stationary wave that are on the same side of the rest position are described as?

1. Out of phase

2. In phase

3. At rest

4. Completely destructive

The correct answer is: In phase

When two points on a stationary wave are on the same side of the rest position, they experience the same phase of oscillation. This means that these points reach their maximum or minimum displacement simultaneously. In wave terminology, we say they are "in phase." In phase means that if you were to observe the oscillations of both points over time, they would rise and fall together, indicating that they are undergoing the same motion at the same time. This concept is important in understanding wave behavior, as points in phase contribute constructively to wave interactions, enhancing the amplitude of the wave at those points. Other phrases like "out of phase," would describe points that reach their maximum and minimum displacements at different times, which does not apply here. Similarly, "at rest" and "completely destructive" describe different conditions not relevant to points oscillating synchronously on the same side of the rest position. Thus, when analyzing stationary waves, identifying points that oscillate together as being "in phase" is essential for understanding their behavior.