Rotary Oscillations

A mass of polar inertia 'I' about its vertical axis is fixed to the end of a solid shaft of length 'l' which is fixed at it's upper end. If the mass is rotated through a small angle and released, it will continue to oscillate. The periodic time of these oscillations can be found as shown below:

David J Grieve. Modified: 10th March 2011, original: 13th November 2001.