Difference Between Wave Velocity and Wave Frequency

Wave Velocity vs Wave Frequency
 

Wave velocity and wave frequency are two very important properties of a wave. The wave velocity describes how fast the energy is propagating. The wave frequency describes how fast the wave is oscillating. Both of these properties are very important in defining and describing the wave. Proper knowledge in these concepts is required in order to excel in fields such as classical mechanics, quantum mechanics and even simple fields like acoustics. In this article, we are going to discuss what wave frequency and wave velocity are, their definitions, the similarities of wave velocity and wave frequency, and finally the differences between wave velocity and wave frequency.

Wave Frequency

Frequency is a concept discussed in periodic motions of objects. To understand the concept of frequency, a proper understanding of periodic motions is required. A periodic motion can be considered as any motion that repeats itself in a fixed time period. A planet revolving around the sun is a periodic motion. A satellite orbiting around the earth is a periodic motion; even the motion of a balance ball set is a periodic motion. Most of the periodic motions we encounter are circular, linear or semi-circular. A periodic motion has a frequency. The frequency means how “frequent” the event is. For simplicity, we take frequency as the occurrences per second. Periodic motions can either be uniform or non-uniform. A uniform can have a uniform angular velocity. Functions such as amplitude modulation can have double periods. They are periodic functions encapsulated in other periodic functions. The wave frequency is a property determined by the source of the wave. For waves such as light and sound, the frequency of a wave stays the same regardless of the medium it travels on.

Wave Velocity

Wave velocity is the speed the wave propagates in a medium. Wave velocity is a property of the medium. This can be described by the term impedance. Impedance is the resistance of the medium to the propagation of the wave. A medium with higher impedance will cause the wave to move slower while a medium with lower impedance will cause the wave to travel faster. The connection between the wave velocity and wave frequency is given by the famous equation V = f λ, where V is the wave velocity, f is the frequency of the wave, and λ is the wavelength. The impedance of the medium also depends on the frequency of the wave.