Buoyancy

Buoyancy : 

Buoyancy Beirut Arab University Faculty of Engineering Department of Civil Engineering Hydraulics CIVE 331

Definition : 

Definition In physics, buoyancy is the upward force, caused by fluid pressure, that keeps things afloat. The net upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body. This force enables the object to float

Who discovered buoyancy? : 

Who discovered buoyancy? Archimedes (a Greek mathematician) discovered buoyancy in 212-250 B.C.. He was hired by the king of Syracuse on the island of Sicily, to find out if his crown was made of true gold or just another metal with a similar physical state. He took a bath one day and realized that his mass displaced the water in the bath tub when he sat down. He then measured a bar of true gold with the same mass as the crown comparability in water. The goldsmith had made the crown with both gold and metal.

Archimedes' principle : 

Archimedes' principle Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.

Importance of Buoyancy : 

Importance of Buoyancy The main importance of buoyancy is whether the object float or sink. And that is determined not by the weight of the object but by its density compared to the density of the fluid as heavy ships

Where buoyant force comes from? : 

Where buoyant force comes from?

Further Studies : 

Further Studies Metacentric height when an object is heeled, the center of buoyancy of that object moves laterally. The point at which a vertical line through the heeled center of buoyancy crosses the line through the original, vertical center of buoyancy is the metacenter. In the diagram to the right the two Bs show the centers of buoyancy of the object in the upright and heeled condition and M is the metacenter The metacenter can be calculated using the formulae: KM = KB + BM

Metacentric height and Stability : 

Metacentric height and Stability The distance between the center of buoyancy and the meta center compared to the distance between the center of buoyancy and the center of gravity of an object determines the stability of an object. If BM > BG then the object is stable If BM < BG then the object is not stable If BM = BG then the object is said to be neutral.

Buoyancy in Civil Engineering : 

Buoyancy in Civil Engineering Well buoyancy its not all about ships, as civil engineers we use buoyancy in building floating structures such as marine oil refineries.

aspect of Buoyancy in every day life : 

aspect of Buoyancy in every day life Egypt is great example of buoyancy variety between salty water and fresh water Although the Nile river is the tallest river in the world and one of the widest but it cannot handle to float big ships due to the fresh water density (1.0 g/ml) While the Red sea or the Mediterian sea can handle to float big ships due to the salty water density (1.025 g/ml)

References : 

References Warsash Maritime Academy.  Ship Stability. Kemp & Young. Archimedes, On Floating Bodies, Proposition