Inertia Disc is a useful physics laboratory instrument developed for demonstrating rotational motion and determining the moment of inertia of a disc about different axes. Its simple yet effective design helps students understand how the distribution of mass and the position of the axis of rotation affect moment of inertia.

This apparatus consists of a uniform metal disc of approximately 15 cm diameter and 6 mm thickness, suspended with the help of a steel wire between two pin-vice clamps. The upper pin-vice clamp is fixed to a wall bracket, while the lower clamp can be attached either at the center or at the circumference of the disc. This arrangement allows the disc to oscillate about different axes for comparative study.

Supplied complete with a wall bracket, the Inertia Disc is suitable for mechanics experiments in school, college, and educational physics laboratories.

Experimental Objectives

To determine the moment of inertia of a disc about its central axis.
To determine the moment of inertia of a disc about an axis passing through its circumference.
To study the effect of change in axis of rotation on the moment of inertia.
To understand the principles of rotational motion and torsional oscillations.