Which factors can cause a change in the speed of sound and why?
In air, temperature can cause a change in speed: higher temperatures equates to greater speeds. This is because as temperature increase, gas becomes less dense (at constant pressure). Less dense gas = less mass for the sound to oscillate which makes it easier for the sound to travel = faster speed of sound. Generally, in solids and liquids, the speed of sounds also varies inversely with density.As in, if the material is denser, the speed of sound will be slower. This can be explained with essentially the same logic as to why sound can move faster through less dense gas. The stiffness of the material also matters, a stiffer material will yield a faster speed of sound. Possibly because sound is forced to oscillate faster because a stiffer material does not want to oscillate slowly or with big oscillations.