often confused with specific gravity density, however, these terms have different meanings.Specific gravity is not the physicochemical characteristics of the substance, as its definition is present gravitational acceleration g = 9,8 m / s ^ 2.In other words, the specific gravity is different from the density of the same is different than the weight of the mass.Density is the ratio of the mass of a substance to its volume and specific gravity - the ratio of body weight to its volume: γ = mg / V.Since the density is the ratio of weight to volume, the formula for finding the proportion of record as follows: γ = ρg.
If necessary, get the share of by calculating the mass and volume, or the experimental method by comparing the values
​​of the pressures.On the basis of the hydrostatic equation to find the value of this quantity as follows: P = Po + γh.This method is used when it is known, all three measured values: P, Po, h.The formula for finding the weight in this case takes the following form: γ = P-Po / h.This equation is widely used to describe the action of communicating vessels.From the experimental data, we can conclude that each substance in the communicating vessels will its height and its rate of spreading along the walls of the vessel.Knowing them, it is possible to calculate the specific gravity of the liquid.
To calculate the proportion of the formula is also used the Archimedes force.It is known that Archimedes force is buoyancy.Imagine being given a load of mass m, which floats on the water surface.On it are two forces, one of which - the force of gravity, and the second - Archimedes force that pushes the body in a direction opposite to the vector mg.Formula Archimedes force is as follows: Farh. = ΡgV.Since the product ρg equal to the specific gravity of the fluid, write the equation in the following form: Farh. = ΓV.Now express this equation variable γ as follows: γ = Farh. / V.