Chapter 13 Section 3 Buoyancy

1. Chapter 13 Section 3Buoyancy Physical Science Hirsh

2. Buoyant Force • Buoyancy is the ability of a fluid to exert an upward force on an object placed in it • Results in the loss of weight of an object while in a fluid • Water exerts an upward force on an object making it easier to lift • The upward force from the water is called the buoyant force • As the pressure increases with depth, the buoyant force increases with depth

3. Float vs sink • Archimedes principle states that the buoyant force on an object is equal to the weight of the fluid displaced by the object • When an object is placed in a fluid, the water it pushes aside is the water that is displaced • If an object is less dense than the fluid it is in, it will float • If an object is more dense than the fluid it is in, it will sink • Water expands when it freezes and becomes less dense, so it floats

4. Float vs Sink • You can also determine whether an object will float or sink by analyzing the forces • When the buoyant force is equal to the weight, an object floats • When the buoyant force is less than the weight, an object sinks