The relation between wave velocity V, frequency f and wavelength λ of a wave is —
V = f λ
Derivation
Let velocity of a wave be V, time period T, frequency f, and wavelength λ.
By definition,
Wavelength λ = Distance travelled by the wave in one time period i.e., in T second
= wave velocity x time period
= V x T
or, VT = λ
Also T = 1/f
or, V(1/f) = λ
or, V = fλ
Therefore,
Wave velocity (V) = Frequency (f) × Wavelength (λ)