Hanging objects may be made to oscillate in a manner similar to a simple pendulum. The motion can be described by "Newton's 2nd law for rotation":
where the torque is
and the relevant moment of inertia is that about the point of suspension. The resulting equation of motion is:
This is identical in form to the equation for the simple pendulum and yields a period:
The period is not dependent upon the mass, since in standard geometries the moment of inertia is proportional to the mass.
For small displacements, the period of the physical pendulum is given by