You will need

- Handbook of physical quantities, the calculator.

Instruction

1

Thus, all long been no secret that

2) Pour water into it, to fix its occupied volume.

3) Weigh the cylinder with water.

4) Calculate the difference of the masses, giving you a lot of

5) Calculate

**the density**of a substance, whether liquid or solid aggregate state can be calculated as mass divided by volume. That is, in order to experimentally determine**the density of**ordinary liquid**water**, you need to:1) Take a measuring cylinder, weigh it.2) Pour water into it, to fix its occupied volume.

3) Weigh the cylinder with water.

4) Calculate the difference of the masses, giving you a lot of

**water**.5) Calculate

**the density of the**known formula2

However, scientists noticed that the density values differ at different temperatures. But the most surprising thing, according to what law this change takes place. So far on this phenomenon puzzled scientists around the world. No one can unravel the mystery and answer the question: "Why is the density when heated from 0 to 3.98 increases, and then decreases to 3.98?" A couple of years ago the Japanese physicist, Masakazu Matsumoto suggested a model of the molecular structure

2) Drop a perpendicular on a graph. Mark the intersection of a line and function.

3) From the resulting points to draw a line parallel to the axis of the temperature on the axis density. The point of intersection is the desired value.Example: Let the temperature

**of water**. According to this theory, creates some polygonal microabrasive - vitrite, which, in turn, dominated by the phenomenon of the lengthening of the hydrogen bonds and shrink the molecules**of water**. However, this theory is still not confirmed experimentally. A graph of the dependence of density on temperature are presented below. To use it you need to:1) Find the desired temperature value on the corresponding axis.2) Drop a perpendicular on a graph. Mark the intersection of a line and function.

3) From the resulting points to draw a line parallel to the axis of the temperature on the axis density. The point of intersection is the desired value.Example: Let the temperature

**of the water**4 degrees, then**the density**after building, is equal to 1 g/cm^3. Both of these values are approximate.3

To determine a more accurate density values, it is necessary to use a table. If there is no data when the desired temperature value, then: 1) Find the values between which is the desired result. For better understanding, consider the example immediately. Let the desired

2) Draw a coordinate plane. Set the axis of abscissa as the temperature, the y-axis as

3) Drop a perpendicular from the desired values of temperature on the period obtained above, mark it as point C.

4) Mark the points D, E, F, as shown on the chart.

5) Now clearly shows that the triangles ADB and AFC are similar. Then the relation is valid:

AD/AF=DB/EF, therefore:

(0,98318-0,97771)/(0,98318-x)=(70-60)/(65-60);

0,00547/(0,98318-x)=2

1,96636-2=0,00547

x=0,980445

Accordingly,

This method of finding the values is called interpolation.

**density****of water**at a temperature of 65 degrees. It is between 60 and 70.2) Draw a coordinate plane. Set the axis of abscissa as the temperature, the y-axis as

**density**. Note on the chart of known points (A and B). Connect them direct.3) Drop a perpendicular from the desired values of temperature on the period obtained above, mark it as point C.

4) Mark the points D, E, F, as shown on the chart.

5) Now clearly shows that the triangles ADB and AFC are similar. Then the relation is valid:

AD/AF=DB/EF, therefore:

(0,98318-0,97771)/(0,98318-x)=(70-60)/(65-60);

0,00547/(0,98318-x)=2

1,96636-2=0,00547

x=0,980445

Accordingly,

**the density****of water**at 65 degrees equals 0,980445 g/cm^3This method of finding the values is called interpolation.

Note

Pay attention to the dimensions.

Useful advice

Carefully carry out all the calculations. Remember that the data in this table are given for ordinary water. From salt water the density is greater.