Rotational Stability Concept

Demonstrations in Rotational Stability

Large colorful pump-action spinning top with concentric rainbow rings, blue conical sections, and a red pump handle, spinning on a small contact point

Standing Top

A pump-action spinning top demonstrates rotational stability: angular momentum allows the top to balance on its point when spinning rapidly but not when stationary. Students observe precession and nutation as …
Two white PVC cylinders on dark fabric, each with different colored marks on their ends — left cylinder has a red X on one end and a blue circle on the other, right cylinder has a blue square on one end and a red rectangle on the other

Rolling and Spinning

Demonstrates that rolling motion is the superposition of translation and rotation. The colored ends of the cylinder make velocity addition visible: the end where translational and rotational velocities cancel appears …
Collection of tops: a large colorful pump-action toy top, a small wooden spinning top, and a red tippe top on a green surface

Tops

The wooden top shows precession and the wobbling motion that develops as a top spins down. The tippe top confounds students: with enough initial angular velocity, it flips over and …
Empty Kleenex tissue box with white and gray leaf pattern, rectangular with plastic dispensing slot on top

Tumbling Box

Demonstrates the intermediate axis theorem (tennis racket theorem). Toss an empty tissue box with spin about each of its three principal axes: rotation is stable about the axes of greatest …
Centrifugal machine with a triangular black metal frame on a base; a small brass ring hangs vertically from a string at the apex; a large hand-crank wheel with wooden handle is visible at right
Safety

Spinning Ring

A suspended ring hangs vertically at rest but reorients to spin horizontally as rotation speed increases. Demonstrates that rotating bodies align with the axis of maximum moment of inertia, minimizing …
Four objects painted in alternating orange and black on a gray surface: a large ring (lower left), a solid disc with radial wedge pattern (upper center), and two rods (right), each with a string and small metal connector for attaching to a drill chuck
Safety

Spinning Object Stability

A ring, disc, and rod suspended from strings and spun by a cordless drill each rise from hanging vertically to spinning horizontally. Demonstrates that at sufficient angular velocity, objects rotate …