Equations · equation
Archimedes' Principle
Fluid Dynamics · c. 250 BCE
- Equation
- F_b = ρ_fluid V g
- Field
- Fluid Dynamics
- Named After
- Archimedes
- Symbols
- F_b the buoyant force, upward · ρ_fluid density of the fluid displaced · V volume of fluid displaced · g gravitational acceleration
- Year
- -250
Significance
A body in a fluid is pushed up by the weight of the fluid it displaces — the pressure below it is higher than the pressure above, by exactly that much. It floats if it weighs less than the fluid it would displace, sinks if more. It is why a mineral's specific gravity can be measured by weighing it in air and in water, why ships of steel float, and why hot air rises.
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