All Problems

Kinetic theory of gases. Boltzmanns Law and Maxwell distribution

Problem 2.99

The velocity distribution of molecules in a beam coming out of a hole in a vessel is described by the function F(v)=Av3emv2/2kTF(v)=A v^{3} \mathrm{e}^{-m v^{2} / 2 k T}, where TT is the temperature of the gas in the vessel. Find the most probable values of (a) the velocity of the molecules in the beam; compare the result obtained with the most probable velocity of the molecules in the vessel; (b) the kinetic energy of the molecules in the beam.

Reveal Answer
(a) vpr=3kT/mv_{p r}=\sqrt{3 k T / m} (b) εpr=kT\varepsilon_{p r}=k T