Phase velocity

The appearance acceleration of a beachcomber is the amount at which the appearance of the beachcomber propagates in space. This is the acceleration at which the appearance of any one abundance basic of the beachcomber travels. For such a component, any accustomed appearance of the beachcomber (for example, the crest) will arise to biking at the appearance velocity. The appearance acceleration is accustomed in agreement of the amicableness λ (lambda) and aeon T as

v_\mathrm{p} = \frac{\lambda}{T}.

Or, equivalently, in agreement of the wave's angular abundance ω, which specifies the amount of oscillations per assemblage of time, and wavenumber k, which specifies the amount of oscillations per assemblage of space, by