Ring on Spinning Hoop - Physics Demonstrations - Ring on Spinning Hoop | Physics Undergraduate Labs

Do not spin faster than necessary. The cylinder fits loosely on the spindle, and excessive speed risks the hoop detaching or the carabiner flying off.

Purpose

A carabiner slides freely on a hoop mounted on a hand-cranked centrifugal machine. As rotation speed increases, the carabiner rises up the side of the hoop, reaching an equilibrium angle set by $\tan\theta = \omega^2 R/g$ .

Metal hoop mounted vertically on a brass spindle attached to a black hand-cranked centrifugal machine, with a small carabiner hanging at the bottom of the hoop

Same apparatus spinning rapidly, with the hoop blurred into a sphere-like pattern and the carabiner's path visible as a bright ring partway up the hoop

Figure 1: Stationary configuration: the carabiner rests at the lowest point of the hoop, which is mounted on the spindle of a hand-cranked centrifugal machine.

Figure 2: At higher rotation speed, the carabiner rises to an equilibrium position partway up the hoop. The motion blur shows the carabiner's circular path as a bright ring.

Centrifugal Machine

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Safety Warnings

Warning: Speed Limitation

Purpose