Moments of inertia and torsional vibrations

Various bodies perform torsional vibrations about axes through their centres of gravity. The vibration period is measured and the moment of inertia determined from this.

Benefits

• Selection of materials allows demonstrating all aspects of moments of inertia in one experiment
• Clear and easy set-up

Tasks

The following will be determined:

1. The angular restoring moment of the spiral spring.
2. The moment of inertia a) of a disc, two cylinder, a sphere and a bar, b) of two point masses, as a function of the perpendicular distance to the axis of rotation. The centre of gravity lies in the axis of rotation.

Learning objectives

• Rigid body
• Moment of inertia
• Axis of rotation
• Torsional vibration
• Spring constant
• Angular restoring moment
• Moment of inertia of a sphere
• Moment of inertia of a disc
• Moment of inertia of a cylinder
• Moment of inertia of a long bar
• Moment of inertia of 2 point masses