you need
  • measuring cup or beaker, scales, ruler, hydrometer.
Guide
1
So, you have the liquid whose density is going to define.Take an empty measuring cup or beaker, place it on the scales and determine the weight of an empty vessel without liquid.Mark it m1, for example.Then pour the liquid into the vessel, the density of which you want to measure.Pour the liquid to the point that it was easy to define its scope (in small beaker marked scale of volume in milliliters).
2
Once you have identified and recorded a volume of liquid (V), put the container back on the scales, but now it is a liquid.Record the new weight and mark it m2.Knowing the weight of the empty vessel m1 and complete vessel m2, determine the mass of liquid m by the formula: m = m2 - m1.Now you can go directly to the d
etermination of the density rho:

rho = m / V,

where m and V - the mass and volume of fluid found above.
3
Remember that the volume of the liquid measured, usually in kilograms per cubic meter or grams per cubic centimeter.Therefore translate the measured values ​​to one or two standard system of measurement units.For example:

1 milliliter = 1 cubic centimeter

1000 liters = 1 cubic meter

1 kilogram = 1000 grams
4
If a vessel with a liquid is large enough, but you know the weight of an empty vessel m1 and masswhen filled m2, it is possible to proceed as follows.First, find the mass of liquid in the vessel according to the formula m = m2 - m1.Next, with a ruler or a tape measure to measure geometrical dimensions of the vessel: for rectangular vessels measure the height, width and length, and the cylindrical - diameter and height.To find the volume of a rectangular container, use the formula:

V = a * b * h,

where a - width, b - length, h - the height of the vessel.
5
To find the volume of a cylindrical vessel, take the formula:

V = (pi * d * d * h) / 4,

where pi - pi equal to 3,14, d - diameter of the vessel, h - the height (the height of the liquid level).After finding

get volume density of the liquid, as in the previous case, the formula Ro = m / V.
6
problem of determining the density is much easier if you have a hydrometer.This device is a glass flask with a float and a scale.Simply put it down into the liquid so that it does not touch the bottom, and the scale at the top of the hydrometer see density liquid.Often motorists use a hydrometer to determine the density of the electrolyte in the battery.