Supertek® Variable Inertia Bar

A classic demonstration of the dependence of angular acceleration on moment of inertia.

This apparatus helps to demonstrate that the torque required to accelerate a flywheel depends upon its moment of inertia rather than its mass. A steel bar (790×12 mm) is mounted at its center on a sleeved spindle. The spindle is extended through a sleeve so that the bar may be rotated by a weight and string. Heavy adjustable masses are mounted on each end of the bar and maybe clamped at any desired position, enabling inertia to be varied.