What affects the speed of sound?

Answer 1

one thing that can propagate sound is if you were to place somthing of which emmits sound in a vacum. The sound waves will propagate in the vacum, because The matter which supports the sound called the medium no longer exists. Source, http://en.wikipedia.org/wiki/Sound

Answer 2

Short Answer:

The speed of a sound wave depends on two properties of a medium, density and elasticity. Changes in temperature and pressure affect these properties and, of course, a change in the chemical or physical composition of a material affect these properties.

Long Answer:

Specifically, for basically all substances, the speed of sound equals the square root of the ratio of the elastic constant divided by the density.

Solids, for instance, generally become less elastic, i.e. the elastic constant gets larger, as temperature is lowered, so the speed of sound should increase.

For air and most gasses, the speed of sound depends on the temperature and not much else (i.e. not pressure) because the density and elasticity change in ways that compensate and leave the speed unchanged.

There are different kinds of sound waves. The usual simple longitudinal (compression) waves that we are familiar with as sound detected by our ear are what we usually mean by the word sound, but there are also transverse matter vibrations also called shear waves. Earthquakes provide an example of both types of these wave, but actually any solid material can have both shear and compression waves. The rules, ratio of elastic constant to density, are true for both types of waves.

The speed of a wave can depend on the frequency. (This is called dispersion.)

We understand this by saying that the elastic constant depends on frequency or wavelength and explaining the cause of that would be a whole different answer to a different question.

As an example of change due to chemical composition, it is well known that humid air propagates sound differently than dry air, but this is basically because it changes the density of air.

An example of a material change that is obvious is the freezing of water. At zero degrees centigrade, water can be either liquid or solid. The two forms propagate sound very differently.

Caveat: This is true for gasses, solids and liquids, but for peculiar things like plasmas it may be different.

Answer 3

In air it is the temperature that effects most the speed of sound, less it is the humididy and realy not it is the atmospheric pressure.

Answer 4

The frequency and amplitude of a wave

Answer 5

• air density (and thus air pressure, temperature, wind and relative humidity); and
• motion of the source (causes Doppler effect).

Answer 6

luckus