Chapter 19, Problem 19.52E

Interpretation Introduction

Interpretation:

The average time between collisions in air at the given conditions is to be calculated.

Concept introduction:

The mean free path of collisions between gaseous atoms is given by the formula given below.

$\lambda =\frac{kT}{\sqrt{2}\pi d^{2}p}$

The average collision frequency of one atom is given by the formula,

$z=\frac{4\pi \rho d^2\sqrt{kT}}{\sqrt{\pi m}}$

The total number of collisions is given by the formula,

$Z=\frac{2\pi {\rho }_1{\rho }_2{\left[\frac{d_1+d_2}{2}\right]}^2\sqrt{kT}}{\sqrt{\pi m}}$