Speed of Sound

The speed of sound, v, in a medium can be determined using the formula v = fλ , whereλ is the wavelength and f is the frequency of the sound wave.

The SI units of v, f and λ are ms^-1 , Hz and metre (m) respectively.

The speed of sound in solids is greater than the speed of sound in liquids which is greater than the speed of sound in gases.

The speed of sound is unaffected by pressure. If the atmospheric pressure changes, the speed of sound in air remains constant.

The speed of sound increases with temperature. At the peak of high-altitude mountains, the speed of sound is less than that at sea level. This is not due to the lower pressures but instead it is because of lower temperatures at the peak of the mountain.