How is wave speed defined?

Wave speed is defined as the distance a wave travels per unit time. This definition emphasizes the relationship between distance and time, allowing us to quantify how quickly a wave propagates through a medium. The wave speed can be calculated using the formula:

Wave speed = Distance / Time

This relationship shows that for a given distance, the time taken for the wave to travel that distance is critical in determining the speed. Understanding wave speed is essential in various contexts, including sound waves, light waves, and water waves, as it helps in predicting how waves will move through different environments.

The other definitions provided do not accurately capture the essence of wave speed. Change in frequency over time relates to wave phenomena but not directly to how fast the wave travels. The energy carried by a wave pertains to its intensity and amplitude but does not define speed. Meanwhile, the amplitude multiplied by frequency refers to a different characteristic related to wave properties but does not describe the wave's travel speed. Thus, defining wave speed as the distance a wave travels per unit time is both concise and correct, aligning it properly within the framework of wave physics.