To show that the change in moment of inertia of a long bar with adjustable weights is proportional the distance from the center of rotation. A weight and a string are wrapped around a disc connected to a long bar by an axle and bearings. When the weight falls it unwinds the string and rotates the weighted rod and disc. Adjust the weights inward to descrease the moment of inertia and increase the rate of rotation. Or adjust the weights outward to increase the moment of inertia and descrease the rate of rotation.
Masses are in the mass drawer.