Any substance has characteristics.And the main characteristics of any substance - weight - or rather, the proportion of the ratio of the weight of the concrete body and the volume occupied by this body.Score this follows from the definition of a mechanical matter.Through it we have a transition to the field definitions of quality.Matter is for us not an amorphous mass, center of gravity tends to his.Well, for example - solar system - all of her body are different in specific gravity (about how to calculate the specific weight - below), as are its weight and its volume.If we take apart our Earth and its shell (lithosphere, hydrosphere, atmosphere), it turns out that they have a specific gravity different and individual.
Similarly, some chemical elements have their weight, only to have the atomic.This is also an expression of the specific gravity.Incidentally, there are only a few elements which may be present in pure form, but everything else -connection usually stable and wearing name simple substances.The lithosphere of our planet more than five hundred, each - with its specific gravity.How to calculate the proportion?And in general, can it be done?
course.It now consider how to calculate the proportion.Better to do it on concrete examples, to make it clearer.
1. For example, you - Head woodworking shop and want to know how to calculate the proportion of the sale of specific goods or the working of the material in this case.It should be known: the value of sales of a particular product, and the total volume.Suppose we have: product - board revenue - 15500 (RUB), specific weight - 81.6%;type of product - timber revenue - 30,000 (£), weight share of 15.8%;product - croaker revenue - 190000 (RUR), the share of 2.6%.Total: revenue - 190 000, while the share of (common), respectively, 100%.How to calculate the proportion of the board?Divide 155000 to 190000, and multiply by one hundred.We get 81.6%.That this is the proportion of the board.
2. How to calculate the proportion of any substance?
The share of reason is often confused with the density, although the concept is completely different.The share does not apply to the physical and chemical characteristics and different from the density as, say, the mass of the weight.
2.1.) Density - the ratio of the mass of the volume and the share - the ratio of weight to volume, this formula can be expressed as: γ = mg / V.If the density is the ratio of the mass of the body given to the volume of the body, the formula for finding the specific weight, respectively, can be written in this form: γ = ρg.
2.2.) If desired, you can find the proportion by volume and weight, or the experimental method, by comparing the values of pressure.Here, in the course will hydrostatic equation: P = Po + γh.But this method is applicable only when all without exception are known measured values.In this case, the formula of finding the specific weight gain as follows: γ = P-Po / h.The equation is generally used to describe the communicating vessels and their actions.On the basis of experimental data is fair conclusion: each substance in communicating vessels, will have its own height and its own rate of spreading along the walls of the vessel in which the substance is.
2.3.) In order to calculate (calculate) the proportion, you can apply another formula (Archimedes force).Remember high school physics lessons?Perhaps only a few affirmative answer.Therefore, we refresh the memory: the Archimedes force buoyancy -power.Suppose given load bearing some weight (denoted by the cargo as the "m"), holding onto the water.At this point, the load affects the two forces, the first - the force of gravity, and the second - Archimedes (buoyancy force, the direction vector is inversely mg).In the formula, the Archimedes force looks like this: Fapx = ρgV.Knowing that ρg equal weight to the specific fluid, the following equation: Fapx = yV, and we conclude: y = Fapx / V.
Difficult?Then we simplify: in order to calculate the proportion, divide the weight by the volume.