✓ Two crowns ✓ Same mass, different density ✓ Vertical slider ✓ Slider works ✓ Slider controls crowns ✓ Slider direction correct ✓ Full slider range ✓ Fall animation ✓ Water displacement ✓ Rising water level ✓ Splash effects ✓ Physics correct ✓ Live mass value ✓ Live volume value ✓ Live density value ✓ Live displaced water ✓ Gilded displaces more ✓ Heureka animation ✓ No external deps ✓ Light bg / dark text ✓ Self-contained HTML
All required features are implemented with correct physics (gold 19.32 g/cm³, alloy 10.50 g/cm³, same 1000 g mass), but buoyancy force is mislabeled as mN when the actual computed values (e.g. ~507 mN) are in units of mN·cm³/g — a dimensional inconsistency — and the water-rise pixel label is cosmetic rather than cm-accurate.
All required features are implemented with correct physics (gold 19.32 g/cm³, alloy 10.50 g/cm³, same 1000 g mass), but buoyancy force is mislabeled as mN when the actual computed values (e.g. ~507 mN) are in units of mN·cm³/g — a dimensional inconsistency — and the water-rise pixel label is cosmetic rather than cm-accurate.