What is Wave Speed Equation (v = fλ)?

In short

The wave speed equation $v = f\lambda$ says that the speed of a wave equals its frequency multiplied by its wavelength.

In simple words

Here $v$ is the speed of the wave in $\text{m/s}$ , $f$ is the frequency in $\text{Hz}$ and $\lambda$ is the wavelength in metres. The speed is set by the medium, and the frequency is set by the source. So when a wave enters a new medium, $v$ and $\lambda$ change while $f$ stays the same.

Example

A sound wave of frequency $440\ \text{Hz}$ has a wavelength of $0.78\ \text{m}$ in air. Its speed is $v = 440\ \text{Hz} \times 0.78\ \text{m} = 343\ \text{m/s}$ .

Also searched as: v = f lambda, wave equation, what is v in the wavelength equation.