Equilibrium

How it works:

Each pan hangs from an equal-length arm. Gravity pulls on the objects, the pans transfer that force to the beam, and the heavier side falls. Equal masses balance because their turning effects—mass × gravity × arm length—match.

The beam, pans, weights and bears share one rigid-body simulation. The bears’ soft wobble is a visual effect; it never changes their mass. This is an interactive, calibrated demonstration, not a certified measuring instrument.

Drag a bear or weight to pick it up. Release above a pan to drop it. Or click an object below: bears go to the left pan, weights to the right. Use the pan buttons to move the selected object. Escape cancels a drag. Reset returns everything to the table.