Buoyancy (Archimedes' Principle)
Drop a uniform object into a tank of fluid — adjust the object's density, the fluid's density, and the object's size to see it settle at its equilibrium floating depth, or sink straight through, exactly as Archimedes' principle predicts.
Preview — sign up free to change the numbers yourself
What you can adjust
- Object density (ρ_obj)
- 200 – 2000 kg/m³
- Fluid density (ρ_fluid)
- 500 – 2000 kg/m³
- Object size (half-height)
- 0.1 – 1 m
Below the fluid's density, the object floats; above it, the object sinks.
1000 kg/m³ is plain water. A denser fluid (like brine or oil-vs-syrup) makes more objects float.
A uniform cube of this half-height. Size doesn't change the equilibrium submerged FRACTION — only how fast it settles.
About this simulation
What it shows
A uniform block is dropped into a tank of fluid, with arrows for its weight and the upward push of the fluid. It settles at a floating depth or sinks.
The key idea
The upward push equals the weight of the fluid the block displaces (Archimedes' principle). A block floats if it is less dense than the fluid, and the fraction submerged is the block's density divided by the fluid's density.
Try this
In 1000 kg/m³ water, raise Object density (ρ_obj) from 600 to 800 kg/m³: the block floats deeper, with 80% submerged instead of 60%.