Speed of Sound
We know that speed is defined as the distance travelled in a given amount of time. The speed of a sound wave is defined as the distance travelled by any point on a wave per unit of time. It means if we take any point on a wave, suppose the point of maximum density, then the distance travelled by this point in unit time is the speed of the wave.
There is another way in which we can find the speed of a sound wave. We think of the speed of the sound wave in terms of one cycle of a wave. A sound wave covers one cycle when it moves from maximum compression to minimum rarefaction and then back to maximum compression, we say that one cycle is completed. This distance is nothing but the wavelength lambda [\lambda]. And the time required to complete this distance is time period T. So we can think of the speed of a sound wave as the distance travelled by a wave equal to the length of one cycle over the time required to complete that distance.
Hence the speed (v) is: the wavelength (\lambda) over the time period (T).
𝑺𝒑𝒆𝒆𝒅(𝒗) = 𝒘𝒂𝒗𝒆𝒍𝒆𝒏𝒈𝒕𝒉(𝛌)/𝑻𝒊𝒎𝒆𝑷𝒆𝒓𝒊𝒐𝒅(𝑻)
There are some factors on which the ‘speed of sound’ depends.
Factors affecting Speed of Sound
- Temperature of the Medium: speed increases when the temperature of the medium
increases. The speed of sound in air at 𝟒𝟎∘C is approximately 355 m/s and at 𝟐𝟎∘C, it is around 344 m/s.
- Nature of Medium: speed of sound also depends on the nature of the medium. It travels fastest in solids than liquids and then