Answer to Question #81097 in Molecular Physics | Thermodynamics for Daniella

Question

A diatomic molecule modeled as two point masses,m1 and m2, slightly separated. If the molecule is oriented along y-axis it has kinetic energu K when it spins about the x-axis. What will its kinetic energy be if it soins at the same angular speed about (a). The z-axis b).the y-axis

Answer 1

a) if the molecule is oriented along the y axis it doesn’t really meter whether it is spinning around the x axis or z axis (both are perpendicular to y axis) so if the molecule spins with the same angular speed around z axis it will have the same energy K
b) as both atoms in the molecule are modeled as points, they do not have any dimensions and so they can not accumulate any rotational energy when spinning around the y axis so the energy will be zero.