What in the air influence the speed of sound?

Answer 1

A sound wave is a pressure disturbance that travels through a medium by means of particle-to-particle interaction. As one particle becomes disturbed, it exerts a force on the next adjacent particle, thus disturbing that particle from rest and transporting the energy through the medium. Like any wave, the speed of a sound waverefers to how fast the disturbance is passed from particle to particle. While frequencyrefers to the number of vibrations that an individual particle makes per unit of time, speed refers to the distance that the disturbance travels per unit of time. Always be cautious to distinguish between the two often-confused quantities of speed (how fast...) and frequency (how often...).

Since the speed of a wave is defined as the distance that a point on a wave (such as a compression or a rarefaction) travels per unit of time, it is often expressed in units of meters/second (abbreviated m/s).

Air is a mixture of gases ! And gases is matter with physical properties, as absorption of sound waves, for example.

Density and humidity.