The application of density in life, what are the applications of density in daily life

As an important property of matter, density has a wide range of applications in scientific research and production and life. In the history of science, argon was discovered by calculating the density of an unknown gas. In 1892 the British chemist Remseys discovered that nitrogen extracted from the air was denser than nitric acid.

and the density of nitrogen extracted from ammonia is high. At first, it thought that the nitrogen extracted from the air was impure, so it tried to remove the carbon dioxide contained in the nitrogen.

Oxygen, moisture, but still found that the nitrogen extracted from the air was dense, from which he deduced that the air may contain an unknown gas, and calculated that this unknown gas was denser than oxygen and nitrogen. Later, after spectroscopic analysis, it was confirmed that the air contained a new gas that was previously unknown, and it was named argon. Density can be used in agriculture to determine the fertility of the soil.

Soil in general contains inorganic substances.

minerals) and organic matter (humus, the more humus the soil is, the more fertile the soil, if the soil contains more minerals, because the density of minerals is greater, this soil is also denser. Generally, the density of soils with a lot of minerals is. If the soil contains a lot of humus, the density of the soil is less, for example, the density of black soil is general.

So the more fertile the soil, the less dense it is. If the density of the soil is high, it can be preliminarily judged that the soil is relatively poor. In agriculture, in addition to the density used to judge the fertility of the soil, the density is also used in seed selection before sowing.

The seeds to be selected are placed in the water, the plump and robust seeds sink to the bottom due to their high density, and the deflated husks and weed seeds float on the surface of the water due to their low density. In industrial production, the raw materials used in some factories are often judged according to their density. For example, some starch manufacturing plants use potatoes as raw materials, and the amount of starch content in potatoes directly affects the output of starch.

Generally speaking, potatoes with a high starch content are denser, so by measuring the density of potatoes, it is possible to judge not only the quality of potatoes, but also the yield of starch. Density is also used in the production of foundries, and the factory needs to estimate how much metal to melt into the mold before casting metal objects, and then it is necessary to calculate the amount of metal to be melted according to the volume of the mold and the density of the metal to avoid waste. Question:

In order to reduce the gravity of the aircraft, the aircraft designer changed the steel part to an aluminum part, reducing its mass by 104kg, and the required mass of aluminum is kg. ( Steel = , Aluminum = .)

In the brine, the eggs float on the sugar, and the tea gets sweeter the lower it goes, and the oil always floats on it when cooking.

As follows:

1. Scientifically.

1. Identify the materials that make up the object.

Density is one of the properties of matter, each substance has a certain density, and the density of different substances is generally different. Therefore, we can use density to identify substances. The method is to determine the density of the substance to be measured, and compare the measured density with the density of various substances in the density table, so that you can identify what kind of substance the object is made of.

2 Calculate the composition of various substances contained in an object.

3 Calculate the mass of an object that is difficult to weigh or the volume of an object with a complex shape.

According to the variant of the density formula: m=v or v=m, the mass and volume of the object can be calculated, especially for some problems where the mass and volume are inconvenient to measure directly, such as calculating the volume of an irregularly shaped object, the mass of a monument, etc.

Second, agriculture.

It is an important criterion for density. In agriculture, it can be used to judge the fertility of the soil, and the soil with more humus is fertile, and its density is generally kilograms.

When we select seeds, we can select seeds according to the sinking and floating conditions of the seeds in the water: the full and robust seeds sink due to high density; Deflated husks and other weed seeds float on the surface of the water due to their low density. In industrial production, for example, the production of starch uses potatoes as raw materials, and generally speaking, the density of potatoes with more starch is larger, so the yield of starch can be estimated by measuring the density of potatoes.

Third, industrially.

Before casting the metal, the factory needs to estimate how much metal will be melted, and the amount of metal required can be calculated based on the volume of the mold and the density of the metal.

Density & Life:

The density of the human body is only g cm, which is only a little more dense than water. Gasoline is less dense than water, so oil stains you see on the road will float on the water. Seawater is denser than water, so it is easier for the human body to float in seawater.

The density of the Dead Sea reaches a density greater than that of the human body, so people can float in the Dead Sea. ）

Hydrogen balloons, hot air balloons, balloons of all kinds.

CO2 fire extinguisher.

For the time being, the swimming circle only thinks about so much.

Identify substances and find mass or volume or density for comparison.

People will drown in water.

There are many applications of density in real life, here are some examples:

a.Geological exploration team members, according to the density of the sample, determine the type of mineral deposit and its economic value;

b.Farmers use the wind to lift the field and sort full wheat grains, shriveled grains, and grass clippings;

c.In agriculture, brine flotation is used for seed selection;

d.In business, identify the concentration of milk and wine (note: generally use a liquid density meter);

e.Vehicle.

In aerospace equipment, high-strength, low-density alloy materials are selected.

composite materials such as glass fiber reinforced plastic;

f.In the product packaging, foam plastic with low density is used.

As a filler, to achieve the purpose of shockproof, easy to transport, low price, etc.;

g.In chemical experiments, extraction experiments separate two different substances, also using examples of separation with different densities.

Below is added a small measurement that also reflects the application of density in real life:

For example: how do you know the length of a thin coil of copper wire?

Methods and Steps].

a.Accurately weigh the mass of a coil of fine copper wire m (kg);

b.If there is a tool for accurate diameter measurement (such as vernier caliper, use vernier caliper to accurately determine the diameter of fine copper wire d(m); If there is only a ruler with a scale, the total diameter of a plurality of thin copper wires is determined by the dense winding method, and then the diameter of a thin copper wire is calculated d(m);

c.Look up the table to get =;

d.According to the formula: v=m, v is calculated; Then, according to v= (1 4) d, l=4v (d) is calculated

1. Geological exploration team members determine the type of mineral deposits and their economic value according to the density of the sample;

2. In business, use a liquid density meter to identify the concentration of milk and wine;

3. In vehicles and aerospace equipment, composite materials such as high-strength hall callers, low-density alloy materials, and glass fiber reinforced plastic chains are selected;

4. In the product packaging, low-density foam plastic is used as filler to achieve the purpose of shockproof, easy transportation, and low price;

5. In chemical experiments, the extraction experiment separates two different substances, which is to use the different densities to achieve the purpose of separation.

1. Identify the materials that make up the object. Determine the density of the substance to be measured, and compare the measured density with the density of various substances in the density table, so as to identify what substance the object is made of;

2 Calculate the composition of various substances contained in an object.

3. It is difficult to weigh the mass of an object or the volume of an object with a complex shape;

4. Determine whether the object is solid or hollow;

5. Calculate the internal pressure and buoyancy of the liquid;

6. Identification of unknown substances;

7. In agriculture, it can be used to judge the fertility of the soil, and the seeds can be selected according to the floating and sinking conditions of the seeds in the water when selecting seeds;

8. In industry, the density of laughter can be used to estimate the amount of metal required to melt a certain metal.

Density is a measure of the mass within a specific volume circle, density is equal to the mass of an object divided by volume, which can be expressed in the symbol, the International System of Units and the Chinese legal unit of measurement.

Generally speaking, no matter what substance it is in, no matter what state it is in, with the change of temperature and pressure, the volume or density will also change accordingly.

The density of a solid or liquid substance changes only slightly when temperature and pressure change. For example, around 0, the temperature coefficient of various metals (the rate of change in the volume of an object when the temperature increases by 1) is mostly around 10-9 power.