The tendency or ability of an object to float.

More than 2,000 years ago, Archimedes discovered the relationship between buoyant force and how much fluid is displaced by an object.

Archimedes principle states:

The buoyant force acting on an object in a fluid is equal to the weight of the fluid displaced by the object.

Buoyancy• The pressure on the

bottom of a submerged object is greater than the pressure on the top. The result is a net force in the upward direction.

Buoyant ForceThe upward force exerted by a fluid on a submerged or floating object.

Buoyancy

• The buoyant force works opposite the weight of an object.

Archimedes’ principle:• Buoyant Force on an object immersed in a

liquid equals the weight of the liquid displaced and the weight of the object if it floats.

•Density and buoyancy: An object that has a greater density than the fluid it is in, will sink. If its density is less than the fluid it will float.

• A solid block of steel sinks in water. A steel ship with the same mass floats on the surface.

Density• Changes in density cause a submarine to

dive, rise, or float.

Density• Changes in density cause a submarine to

dive, rise, or float.

Density• Changes in density cause a submarine to

dive, rise, or float.