Define buoyancy and centre of buoyancy with examples

Buoyancy is the upward force exerted by a fluid on an object immersed in it. The buoyant force is equal to the weight of the fluid displaced by the object. The center of buoyancy is the point in an object where the buoyant force acts.

Here are some examples of buoyancy

A boat floating in water. The buoyant force of the water counteracts the weight of the boat, keeping it afloat.

A cork floating in water. The cork is less dense than water, so it displaces more water than its own weight. The buoyant force of the water is

greater than the weight of the cork, keeping it afloat.

An anchor sinking in water. The anchor is more dense than water, so it displaces less water than its own weight. The buoyant force of the water is less than the weight of the anchor, causing it to sink.

The center of buoyancy is located at the center of gravity of the volume of fluid displaced by the object. For example, the center of buoyancy of a boat is located at the center of the water displaced by the boat's hull.

The center of buoyancy is important for the stability of objects floating in fluids. If the center of buoyancy is below the center of mass of the object, the object will be stable. If the center of buoyancy is above the center of mass, the object will be unstable and may tip over.

Here are some examples of how the center of buoyancy affects stability:

A canoe is stable because the center of buoyancy is below the center of mass of the canoe. This means that the canoe will tend to right itself if it tips over.

A sailboat is stable because the center of buoyancy is below the center of mass of the sailboat. However, the center of buoyancy can move depending on the angle of the sails. If the sails are angled too far, the center of buoyancy can move above the center of mass, causing the sailboat to capsize.

A submarine is stable because the center of buoyancy can be adjusted by pumping water in and out of the ballast tanks. This allows the submarine to float at different depths.