🧲 Magnet Train: Flip the Poles, Pull, Push and Race

Kids put magnets beside a toy track and flip the red and blue poles on three little train cars to make them pull together and couple, push apart, float and race to the flag. Magnet force fades with distance by a simple inverse-power law; a field-line view and a built-in numerical check (force-distance fit and energy conservation) are included.

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install