Archimedes' Principle
The upthrust on a body immersed in a fluid equals the weight of the fluid displaced by the body.
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Archimedes' principle
When a body is fully or partially immersed in a fluid, the upward buoyant force (upthrust) is equal to the weight of the fluid displaced by the body. So upthrust = weight of displaced fluid = Vρg (V = volume displaced, ρ = fluid density). A body floats when weight = upthrust.
✔ Key takeaway: Upthrust = weight of displaced fluid.
💭 Think about this:
Why does a ship made of steel float when a steel block sinks?