The liquid, like any other substance, has volume and mass.
Accordingly, for measuring its quantity, measures of volume and weight measures are used.
To determine how much a liquid weighs a certain volume, it is not necessary to weigh it, the more such an opportunity is not always available.
A simple experiment
The volume of water is most often measured in liters. It is not difficult to weigh 1 liter of distilled water. For this we need:
- electronic balance-
- Measured dishes-
Distilled water can be bought in the store,Where they sell auto parts and other goods for motorists, as well as in the pharmacy. It is better to take a glass jar. Chemical dishes for experiments with water are not necessary. Weigh the empty jar. Pour into it exactly 1 liter of water and weigh again. Subtract the first from the second result. You get a lot of water. And you make sure that it is equal to 1 kg. If you have water from a tap or from a well, it can weigh a little more at the expense of the salts dissolved in it. The error is usually insignificant, and for school experience the difference can be neglected.
We translate the measures of volume
Remember what is 1L. It is equal to one thousand cubic centimeters, that is one cubic decimetre. In turn, one cubic meter - one thousand cubic decimeters. To see this, it's enough to build a ratio of 1 m = 10 dm to the cube. How much does 1 dm3 weigh, you have already calculated. Remember what a ton is equal to. It is equal to 1000 kg. That is, one ton weighs 1000 dm3 of water. It turns out that 1 cubic meter of distilled water will weigh exactly 1 ton.
Distilled water is a kind ofA reference that can be used for weighing other objects. After all, nothing is worth turning a jar of water into weights. Pour a certain amount of water into it, you will know exactly how much it weighs, so you can use this "weights" for working with mechanical scales. Calculate the ratio of mass and volume of other liquids so simply does not work. It is necessary to know one more quantity - density. You can find it in the table of densities of various chemicals. Calculate the density by the formula? = M / V, where m - mass, and V - volume. To find the mass, you need to multiply the density by the volume. The same formula can be used to calculate the mass of 1m3 of water. The density of water is 0.9982 g / cm ?, but in calculations that do not require very high accuracy, it is usually taken as 1 g / cm ?. Substituting this value in the formula, you get m =? * V = 1 g / cm? * 1000000 cm3 = 1,000,000 g = 1000 kg = 1 ton.
In the same way, we can calculate the massRigid body, if it can not be weighed, but it is possible to measure the volume and it is known from what substance it is made. To calculate the mass of a body consisting of several parts, we can take the average density, but the calculations will be with a large error.