buoyancy

Buoyancy is the force that pushes up on objects that are in water.

Buoyancy is what makes boats float and why things sink. It is caused by the fact that water is denser than air. This means that water molecules are more tightly packed together than air molecules. When an object is placed in water, the water molecules push up on the object with a force called buoyancy. The amount of buoyancy depends on the volume of the object and the density of the water.

Here are some examples of buoyancy:

• A boat floats because the volume of the boat is greater than the volume of water that it displaces.
• Boat floating on water
• A rock sinks because the volume of the rock is less than the volume of water that it displaces.
• Rock sinking in water
• A balloon filled with air floats because the air inside the balloon is less dense than the water outside the balloon.

The buoyancy of a boat is what keeps it afloat.