How is the speed of a wave generally calculated?

The speed of a wave is calculated using the fundamental relationship between speed, wavelength, and frequency. The correct formula expresses that the speed of a wave is equal to its wavelength multiplied by its frequency. In this context, the wavelength is the distance between consecutive peaks (or troughs) of a wave, while frequency refers to how many wavelengths pass a specific point in one second.

The importance of this relationship lies in its application across various types of waves, including sound waves and electromagnetic waves. When you increase the frequency of a wave, while keeping the wavelength constant, the speed will also increase proportionally. Conversely, if the wavelength increases, the speed of the wave will similarly increase, given that the frequency remains constant.

This formula is foundational in wave mechanics and is critical for understanding phenomena such as why sound travels faster in water than in air, and why different frequencies of light travel at the same speed in a vacuum but at different speeds in various media.

Other options presented do not adhere to the fundamental wave relationship and provide incorrect mathematical relationships for calculating wave speed.