Explain Archimedes Principle ?
Answers
Explanation:
Background Reading
Science historians generally agree that the idea for his principle occurred to Archimedes as he entered a bath pool. As he waded into deeper water, the force on his feet became less.
Archimedes' Principle is that an object totally or partially immersed in a fluid (liquid or gas) is buoyed (lifted) up by a force equal to the weight of the fluid that is displaced.
It has numerous applications, one of which is the determination of density and specific gravity. In the following discussion, the subscripts S, W, and A represent the Substance, Water, and Air, respectively.
Density is the mass per unit volume of a substance. rho = M / V
Specific Gravity is the ratio of the density of the substance to the density of water. SG = rhoS / rhoW.
The metric system unit GRAM is defined to be the mass of one cubic centimeter (one milliliter) of pure water at 3.98oC. Thus, for water rhoW = 1 gram/cm3 and, if errors due to impurities and/or temperatures are tolerable, this is a great convenience. The definitions given above suggest various methods for determining specific gravity.
SG = rhoS / rhoW = (MS / VS) / (MW / VW) = (MSg / VS) / (MWg / VW) = (WS / VS) / (WW / VW)
The definition of SG was applied for the first equality; the definition of density was applied for the second equality. For the third equality, the numerator and denominator were multiplied by "g". WS is the weight of the substance measured in air; WW is the weight of the water displaced by the substance when it is immersed.
In some circumstances, the volume of the substance is equal to the volume of the water. In particular, when a solid object is completely immersed in water, the volume of the water displaced must be equal to the volume of the object. Furthermore, by Archimedes' Principle, upon immersion the object would receive a buoyant force equal to the weight of the water displaced. Thus, an object weighed in air and then weighed while immersed in water would have an effective weight that was reduced by the weight of the water displaced, if the buoyant force of the air is negligible. When weighed in air, the object receives a buoyant force equal to the weight of the air displaced by the object. However, the density of air is small enough (compared to the density of most solids) to allow this buoyant force to be neglected when weighing most solids in air. (rhoair = 1.3 x 10-3 grams/cm3)
Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces. Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse.