you need
  • know the volume of the substance, as well as its density.
volume - is the ability of the body to accommodate a certain amount of any material, it is measured in cubic meters, cc, etc. km³Therefore, to find the mass of the body is required to find only the density of its substance .
Density - a physical quantity, which is defined as the ratio of the mass of the body to the volume which it occupies.According to this definition, the density is measured in kg / m³.Hence it follows the form of the formula for finding the density of a substance : p = m / VEtoy formula will not have to use often, because almost all the density of substances are already known and counted.All these data are in Table densities.
Now, having understood with missing data, can be taken for
determination of mass substance .This can be done using the formula: m = p * VPrimer: Need to find a lot gasoline, which amounts to 50 m³.As seen from the problem.the amount of the original substance known, is required to find the density.According to the table of densities of various substances, the density of gasoline is 730 kg / m³.Now find a lot of gasoline, you can: m = 730 * 50 = 36500 kg or 36.5 tOtvet: plenty of gasoline is 36.5 m