Q7.20 The oxygen molecule has a mass of and a moment of inertia of
about an axis through its centre perpendicular to the lines joining
the two atoms. Suppose the mean speed of such a molecule in a gas is and
that its kinetic energy of rotation is two thirds of its kinetic energy of translation.
Find the average angular velocity of the molecule.
We are given the moment of inertia and the velocity of the molecule.
Let the mass of oxygen molecule be m.
So the mass of each oxygen atom is given by :
Moment of inertia is :
or
or
We are given that :
or
or
or