you need

- know the volume of the substance, as well as its density.

Guide

1

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

**.** 2

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.** 3

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** Note

addition to body weight, there is aanother related to her size - the body weight.They are not in any way be confused, because the body weight - a measure of the impact on the support, and the weight of the body - the power of influence on the Earth's surface.Besides these two variables have different units of measurement: body weight is measured in Newtons (as well as any other force in physics), and the mass, as noted earlier, is measured in kilograms (according to SI) or grams (according to the CGS system).

Helpful Hint

mass of matter in life is measured by the simplest and most ancient instrument - the balance, which is made based on physical laws balances.According to him, the balance is in equilibrium only if both ends of the tool body will be of equal mass.Therefore, use of weights was introduced weights - a kind of standard with which to compare the mass of other bodies.