\(v = f\lambda\)

where:

* \(v\) is the speed of the wave in meters per second (m/s),

* \(f\) is the frequency of the wave in Hertz (Hz), and

* \(\lambda\) is the wavelength of the wave in meters (m).

This equation can be derived from the definition of wave speed:

$$v = \frac{d}{t}$$

where \(d\) is the distance the wave travels in time \(t\). For a sinusoidal wave, the distance between two adjacent peaks or troughs is one wavelength \(\lambda\). The time between two adjacent peaks or troughs is the period \(T\) of the wave, which is the reciprocal of the frequency \(f\). Therefore, we can write:

$$v = \frac{\lambda}{T} = \lambda f$$