Module 4 : Kinetic Theory of Gases

Lecture 6 : Applications of Maxwell-Boltzmann Distribution

As discussed in the previous lecture, Maxell-Boltzmann velocity distribution function is given by


(4.105)

Variation of dNv/dv with v for three different temperatures T1, T2 and T3 is presented in Fig. 4.14. Area under the dNv/dv versus v represents the total number of molecules. Thus for a system with different temperatures, all the areas will be same.

Consider an elemental strip of thickness dv at a distance v from the origin under the curve for the temperature T1. This elemental strip  represents the number of molecules dNv having velocities lying between v and v + dv . Total number of molecules N can be obtained by integrating the  from v = 0 to v = ∞. The maxima of these curves (Fig.4.14) fall on an equilateral hyperbola


Fig.4.11 Velocity distribution function at different temperature,

Substituting α and β in (Eq. 4.91) for ρ, we get


(4.106)

The speed distribution function for each of the three velocity components may similarly be determined. From  Eqs. (4.53) and (4.72),

(4.107)

 

 

 

(4.108)