Variable Inertia Bar

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 x 12 mm is mounted at its centre 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.