1. Cornell Notes 3.3 – Buoyancy
January 9, 2017 – page 97

2. What is Buoyancy?
Buoyancy is the upward force exerted upon an object by the fluid in which it is immersed. This means:
Buoyancy is a force (push or a pull)
Buoyancy pushes upward
The fluid (liquid or gas) is doing the pushing

3. How Can We Measure Buoyancy?
If something is floating in a fluid, then the buoyant force is equal to the weight of the object
If something sinks in a fluid, then the buoyant force is equal to how much lighter the object feels when it sinks into the fluid
In the latter case Buoyant Force = Actual Weight – Underwater Weight

4. Archimedes’ Principle
Archimedes’ Principle states that the buoyant force on an object is equal to the weight of the fluid that the object displaces
Imagine a hole that the object puts in the water
Now imagine filling that hole with water
The weight of the water that fills the hole is the same as the buoyant force on the object
Denser fluids are heavier, so they are more buoyant

5. Buoyancy in action