All Problems

Kinetic theory of gases. Boltzmanns Law and Maxwell distribution

Problem 2.86

In the case of gaseous nitrogen find: (a) the temperature at which the velocities of the molecules v1v_{1} =300 m/s=300 \mathrm{~m} / \mathrm{s} and v2=600 m/sv_{2}=600 \mathrm{~m} / \mathrm{s} are associated with equal values of the Maxwell distribution function F(v)F(v) (b) the velocity of the molecules vv at which the value of the Maxwell distribution function F(v)F(v) for the temperature T0T_{0} will be the same as that for the temperature η\eta times higher.

Reveal Answer
 (a) T=m(v22v12)4kln(v2/v1)=330 K (b) v=3kT0mηlnηη1\text { (a) } T=\frac{m\left(v_{2}^{2}-v_{1}^{2}\right)}{4 k \ln \left(v_{2} / v_{1}\right)}=330 \mathrm{~K} \text { (b) } v=\sqrt{\frac{3 k T_{0}}{m} \frac{\eta \ln \eta}{\eta-1}}