# How does the frequency of a wave affect the wavelength?

A specific type of wave in a specific medium has a constant speed. For example electromagnetic waves have a speed of $3.0 \cdot {10}^{8} m {s}^{-} 1$ in a vacuum, whereas in glass they have a speed of approx. of $2.0 \cdot {10}^{8} m {s}^{-} 1$.
Wave speed, frequency and wavelength are related by this equation: v=fλ. If the medium does not change then $v$ is a constant and wavelength and frequency are inversely proportional.