Waves and Oscillations - Continuous Media : Vibrations of Air Column - Equation of Motion скачать в хорошем качестве

Waves and Oscillations - Continuous Media : Vibrations of Air Column - Equation of Motion

Air or any other gas can be regarded as a continuous medium at ordinary pressures. Since at ordinary pressure the particle density is very large,therefore the average distance between the molecules is very small and,as an approximation,we imagine the number of molecules becoming infinite and the distance between them tending to zero. A column of gas then behaves as if it were continuous. The gas enclosed inside an element acts like a compressed spring which would like to extend itself;since the gas exerts an outward pressure on the walls of the element. This system has internal elasticity. Taking these facts under account,the equation of motion has been obtained.