| A18-1 | Oscillating ring. |
| Purpose: | To show physical pendula. |
| Description: | A ring is suspended from a knife edge at a point on its periphery so it acts as a physical pendulum in its plane. A simple pendulum whose length is equal to the diameter of the ring is suspended beside it so the equality of periods can be observed. |
| References: | My-3. |
| Equipment: | Ring, knife edge, simple pendulum. |