# Wave Speed Formula

A wave is defined as a kind of disturbance in a moving medium, for example, the waves of the ocean move in a medium and can see the movement of wave crest from one point to the other in a given time period. The motion of an object can be described regarding the speed which describes the velocity of the object.

A wave is visualized when a source vibrates and disturbs a particle in the medium. This can usually be seen in the case of tuning fork or ripples in water when a body is dropped, etc.

The number of waves travelled in one second is the frequency and the time period is the reciprocal of the frequency of the waves. Wavelength is the distance between the corresponding points in any two consecutive waves.

The Wave speed formula which involves wavelength and frequency is given by:

v = f λ

Where,

v = velocity of the wave,

f = frequency of the wave,

λ = wavelength.

Example1

A light wave travels with a wavelength of 600 nm. Determine its frequency.

Solution:

Given:

Wavelength λ = 600 nm,

Velocity of light v = $3\times 10^{8}m/s^{2}$

The frequency is calculated by,

f = v / λ

=$3\times 10^{8}/600\times 10^{-9}$

$f=5\times 10^{14}$ Hz

The frequency of the light wave is $f=5\times 10^{14}$ Hz

Example 2

A sound wave has a wavelength of 1.5 mm. Determine its frequency.

Solution:

Given:

Wavelength λ = 1.5 mm,

Velocity of sound v = 343.2 m/s.

The frequency is calculated by,

f = v / λ

= 343.2 / $1.5\times 10^{-3}$

$f=228\times 10^{3}$Hz

The frequency of the light wave is $f=228\times 10^{3}$ Hz