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PHYSICAL BODIES. PHYSICAL PHENOMENA
1. Indicate what refers to the concept of “physical body” and what to the concept of “substance”: airplane, spaceship, copper, fountain pen, porcelain, water, car.
2. Give examples of the following physical bodies: a) consisting of the same substance; b) from various substances the same name and purpose.
3. Name physical bodies that can be made of glass, rubber, wood, steel, plastic.
4. Indicate the substances that make up the following bodies: scissors, glass, football camera, shovel, pencil.
5. Draw a table in your notebook and distribute the following words in it: lead, thunder, rails, blizzard, aluminum, dawn, blizzard, Moon, alcohol, scissors, mercury, snowfall, table, copper, helicopter, oil, boiling, blizzard, shot , flood.
6. Give examples of mechanical phenomena.
7. Give examples of thermal phenomena.
8. Give examples of sound phenomena.
9. Give examples of electrical phenomena.
10. Give examples of magnetic phenomena.
11. Give examples of light phenomena.
12. Draw the table below in your notebook and write down words related to mechanical, sound, thermal, electrical, light phenomena, the ball is rolling, lead is melting, it is getting cold, thunder is heard, snow is melting, stars are twinkling, water is boiling, dawn is coming, echo , a log floats, a clock pendulum oscillates, clouds move, a thunderstorm, a dove flies, lightning flashes, leaves rustle, an electric lamp burns.
13. Name two or three physical phenomena that are observed when fired from a cannon.
MEASUREMENT OF PHYSICAL QUANTITIES
14. Imagine a 3-kopeck coin and a soccer ball. Mentally estimate how many times the diameter of the ball is greater than the diameter of the coin. (To check your answer, see Table 11.)
15. a) The thickness of a hair is 0.1 mm. Express this thickness in cm, m, µm, nm. b) The length of one of the bacteria is 0.5 microns. How many of these bacteria would fit closely together over a length of 0.1 mm, 1 mm, 1 cm?
16.B Ancient Babylon The unit of length was taken to be the distance traveled by an adult during the time the Sun's disk emerged from the horizon. This unit was called a stage. Could such a unit of length be accurate? Explain your answer.
17. What is the length of the block shown in Figure 1?
18. Figure 2 shows how the diameter of a ball can be measured. Define it. Using the above method, determine the diameter of the ball you are playing with.
19. Figure 3 shows parts of bars and rulers. The left ends of the bars coincide with the zero marks of the rulers, which is not shown in the figure, and the right ends relative to the numerical marks of the scale are located as shown in the figure. Determine by eye the length of each block if
the price of dividing the rulers is 1 cm.
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Fig 3
20. Taking into account what fraction of the scale division value can you measure the lengths of small objects with the rulers shown in Figure 4, a, b, c, d?
21°. To determine the diameter of the wire, the student wound 30 turns tightly around a pencil, which took up a part of the pencil 3 cm long (Fig. 5). Determine the diameter of the wire.
22°. Determine the circumference of the head of a screw or nail once using the method shown in Figure 6, and another time by measuring the diameter and multiplying it by the number of l. Compare the measurement results and write them down in your notebook.
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23. Take several identical coins, fold them as shown in Figure 7, and measure the thickness of the resulting stack with a millimeter ruler. Determine the thickness of one coin. In which case will the thickness of one coin be measured better: with a small number of coins or with a large number of coins?
24. How to use a measuring ruler to determine the average diameters of small homogeneous objects, for example, millet grains, lentils, pinheads, poppy seeds, etc.?
25. a) During the construction of a house, a reinforced concrete slab 5.8 m long and 1.8 m wide was laid. Determine the area occupied by this slab, b) In any circus in the world, the diameter of the arena is 13 m. What area does the arena occupy in a circus?
26. What length will be the strip consisting of pieces with an area of \u200b\u200bI cm 2, cut from a sheet with an area of 1 m 2?
27. Having measured the diameter of the circle shown in Figure 8, calculate its area. Determine the area of a circle by counting the squares in it. Compare your numerical results.
28. Determine the volume of a rectangular block whose length is 1.2 m, width 8 cm and thickness 5 cm.
29. Having measured the length, width and height of your room, determine its volume.
30. The height of the granite column is 4 m, the base of the column is a rectangle with sides 50 and 60 cm. Determine the volume of the column.
31. What are the volumes of liquids in the beakers shown in Figure 9?
32. What are the similarities and differences between the beaker scales shown in Figure 10?
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33. A body of irregular geometric shape is lowered into a beaker with water (Fig. 11). Determine the price of dividing the beaker and the volume of the body.
34. How to determine the volume of one pellet if given a beaker, a shot, and water?
35. Using Figure 12, explain how you can determine the volume of a body that does not fit in a beaker.
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36. With what accuracy can time be measured with the stopwatch shown in Figure 13?
37. The school's athletics winner ran a 100 m distance in the time shown on the stopwatch in Figure 13. Express this time in minutes, hours; milliseconds, microseconds.
3§. At night the air temperature was -6° C, and during the day +4° C. By how many degrees did the air temperature change?
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39. Determine the scale division value of each thermometer (Fig. 14). What is the maximum temperature that can be measured with thermometers shown in Figure 14, b, d; minimal (Fig. 14, a, d)? What temperature does each thermometer show?
STRUCTURE OF MATTER
40. Oil is compressed in a thick-walled steel cylinder. At high pressure, oil droplets protrude on the outer walls of the cylinder. How can this be explained?
41. In the photograph, the apparent diameter of a molecule of a certain substance is 0.5 mm. What is the actual diameter of a molecule of a given substance if the photograph was taken using an electron microscope with a magnification of 200,000 times?
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42. A drop of oil with a volume of 0.003 mm3 spread over " surface-water thin layer and occupied an area of 300 cm2. Taking layer thickness equal to the diameter oil molecules, determine this diameter.
43. The length of the mercury column in the tube of the room thermometer has increased. Did the number of mercury molecules increase? Has the volume of each mercury molecule in the thermometer changed?
44. Is it possible to say that the volume of gas in the vessel equal to the sum volumes of its molecules?
45. At the same temperature, do the spaces between the molecules of any substance that are in solid, liquid and gaseous states differ?
46. Under the influence of the load, the rubber cord lengthened. Have the spaces between the rubber particles changed?
47. Under the influence of the load, the piston in the cylinder dropped (Fig. 15). When the load was removed, the piston took its previous position.
position /. How did the ratio of the volume of air under the piston to the sum of the volumes of its molecules change?
48. Give an example of an experiment confirming that a substance consists of molecules separated by spaces.
49. Are the volumes and composition of the molecules of cold and hot water?
50. Are the volumes and composition of molecules the same for different substances?
51. Given is the ratio of an arbitrary volume of water to the sum of the volumes of molecules of the same water and the ratio of the same volume of steam to the sum of the volumes of molecules of the same steam. Which attitude is greater?
52. How do the spaces between the particles of a copper rivet change when heated and cooled?
53. What explains the increase in the length of the wire when it is heated?
54. Why does the length of the rail decrease when it cools?
55. Why do precision measuring instruments indicate temperature (usually 20°C)?
MOLECULE MOVEMENT AND BODY TEMPERATURE
56. What explains the spread of odors of gasoline, smoke, mothballs, perfume and other odorous substances in the air?
57. Gas molecules move at speeds of the order of several hundred meters per second. Why don’t we immediately smell the smell of ether or gasoline spilled near us in the air?
58. An open vessel with carbon dioxide was balanced on a scale. Why did the balance of the scales become disrupted over time?
59. A children's rubber balloon filled with hydrogen becomes slightly inflated after a few hours. Why?
60. Why does the smoke from a fire, as it rises, cease to be visible even in calm weather?
61. Why does diffusion proceed much faster in gases and liquids than in solids?
62. In an old book, sheets of thin transparent paper are glued in front of the pages with drawings. Why did the imprints of the drawing appear on the sides of this paper in contact with the drawings over time?
63. The sea animal squid, when attacked, throws out a dark blue protective liquid. Why does the space filled with this liquid become transparent after some time, even in calm water?
64. If you examine a drop of highly diluted milk through a microscope, you can see that small drops of oil floating in the liquid are continuously moving. Explain this phenomenon.
65. Identical pieces of sugar were thrown into glasses of water at the same time. In which glass was the initial temperature of the water higher (Fig. 16)?
66. Why is it not recommended to leave a wet dark-colored cloth in contact with a white cloth for a long time? Explain the phenomenon occurring.
67. How can diffusion in solids be accelerated?
68. Where is it better to store a children's rubber ball filled with hydrogen: in a cold or warm room?
69. One jug of milk was put in the refrigerator, the other was left in the room. Where will the cream settle faster?
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INTERACTION OF MOLECULES
70. The molecules of a solid are in continuous motion. Why don't solids break up into individual molecules?
71. Why can’t we put a broken pencil back together so that it becomes whole again?
72. Why doesn’t dust rise on the road after rain?
73. Why does it take significantly more force to separate sheets of paper moistened with water than when turning over dry pages of a book?
74. Why do they write on a blackboard with chalk and not with a piece of white marble? What can be said about the interaction between particles of these substances?
75. Which substances (lead, wax, steel) have the greatest attraction between particles; least?
76. Plane-parallel gauge blocks (Johansson tiles) are polished so that upon contact they stick to each other and are mutually held (Fig. 17). Explain the reason for this phenomenon.
77. Welding of metal parts can also be done in a cold way, if, after connecting them, you squeeze them very hard. Under what conditions can such welding be performed?
78. A glass plate suspended on a rubber cord was lowered until it came into contact with the surface of the water (Fig. 18). Why does the cord stretch when lifting the record?
79. In which state - solid or liquid - is the attraction between lead molecules greater?
80. Oil is relatively easily removed from a clean copper surface. It is impossible to remove mercury from the same surface. What can be said about the mutual attraction between oil and copper molecules, mercury and copper?
81. Molecules of a substance are attracted to each other. Why are there gaps between them?
82. What is common between gluing paper and soldering metal products?
83. What is the difference between welding metal parts and soldering metal parts?
Chinese products?
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THREE STATES OF MATTER
84. In what state are the following substances at room temperature: water, sugar, air, tin, alcohol, ice, oxygen, aluminum, milk, nitrogen? Write your answers in the table by drawing it in your notebook.
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State |
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gaseous |
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85. Is it possible to fill an open vessel with gas to 50% of its capacity?
86. A closed bottle is half filled with mercury. Can we say that there is no mercury in the top half of the bottle?
87. Can oxygen and nitrogen exist in a liquid state? 88.* Can mercury be in a gaseous state?
iron, lead?
89. On a summer evening, fog formed over the swamp. What state of water is this?
90. On a frosty winter day, fog formed over the ice hole in the river. What state of water is this?
91. The dog “takes” a fresh, although invisible, trail (for example, a hare). However, over time, she cannot smell it. Explain this phenomenon.
92. Kerosene was stored in a polystyrene flask for a long time. If we pour milk into this flask, even a very thoroughly washed one, we will still smell kerosene in it. Explain why.
93. A piece of tin was heated, and it acquired a liquid state. How did the movement and location of the tin pieces relative to each other change?
94. The water evaporated and turned into steam. Did the water molecules themselves change? How did their location and movement change?
In today's article we will discuss what the physical body is. You have come across this term more than once during your years of schooling. We first encounter the concepts of “physical body”, “substance”, “phenomenon” in natural history lessons. They are the subject of study in most branches of special science - physics.
According to "physical body" means a certain material object that has a form and a clearly defined external boundary that separates it from external environment and other bodies. In addition, the physical body has characteristics such as mass and volume. These parameters are basic. But besides them there are others. It's about about transparency, density, elasticity, hardness, etc.
Physical bodies: examples
To put it simply, we can call any of the surrounding objects a physical body. The most common examples are a book, a table, a car, a ball, a cup. Physicists call a simple body something whose geometric shape not difficult. Composite physical bodies are those that exist in the form of combinations of interconnected simple bodies. For example, very conventionally the human figure can be represented as a collection of cylinders and balls.
The material from which any of the bodies consists is called substance. Moreover, they can contain either one or a number of substances. Let's give examples. Physical bodies - cutlery (forks, spoons). They are most often made of steel. A knife can serve as an example of a body consisting of two different types substances - a steel blade and a wooden handle. And such a complex product as cellular telephone, is made from much more"ingredients".
What are the substances?
They can be natural or artificially created. In ancient times, people made all the necessary items from natural materials (arrowheads - from clothes - from animal skins). With the development of technological progress, substances created by man appeared. And at present these are the majority. Classic example The physical body of artificial origin can serve as plastic. Each of its types was created by man in order to provide the necessary qualities of a particular item. For example, transparent plastic is for glasses lenses, non-toxic food grade plastic is for dishes, and durable plastic is for a car bumper.
Any item (from a high-tech device) has a number of certain qualities. One of the properties of physical bodies is their ability to be attracted to each other as a result of gravitational interaction. It is measured using a physical quantity called mass. According to physicists, the mass of bodies is a measure of their gravity. It is denoted by the symbol m.
Mass measurement
This physical quantity, like any other, can be measured. To find out what the mass of any object is, you need to compare it with a standard. That is, with a body whose mass is taken as unity. The International System of Units (SI) is the kilogram. This “ideal” unit of mass exists in the form of a cylinder, which is an alloy of iridium and platinum. This international sample is stored in France, and copies of it are available in almost every country.
In addition to the kilogram, the concept of ton, gram or milligram is used. Body weight is measured by weighing. This is a classic method for everyday calculations. But in modern physics there are others that are much more modern and highly accurate. With their help, the mass of microparticles, as well as giant objects, is determined.
Other properties of physical bodies
Shape, mass and volume are the most important characteristics. But there are other properties of physical bodies, each of which is important in a certain situation. For example, objects of equal volume can differ significantly in their mass, that is, have different densities. In many situations, characteristics such as brittleness, hardness, elasticity or magnetic properties are important. We should not forget about thermal conductivity, transparency, homogeneity, electrical conductivity and other numerous physical properties of bodies and substances.
In most cases, all such characteristics depend on the substances or materials from which the objects are composed. For example, rubber, glass and steel balls will have completely different sets of physical properties. This is important in situations where bodies interact with each other, for example, studying the degree of their deformation upon collision.
About accepted approximations
Certain branches of physics consider the physical body as a kind of abstraction with ideal characteristics. For example, in mechanics, bodies are represented in the form material points, having no mass and other properties. This section of physics deals with the movement of such conditional points, and for solving the problems posed here, such quantities are not of fundamental importance.
In scientific calculations, the concept of an absolutely rigid body is often used. This is conventionally considered to be a body that is not subject to any deformation, with no displacement of the center of mass. This simplified model allows one to theoretically reproduce a number of specific processes.
The section of thermodynamics uses the concept of an absolutely black body for its purposes. What is it? A physical body (some abstract object) capable of absorbing any radiation falling on its surface. At the same time, if the task requires it, they can emit electromagnetic waves. If, according to the conditions of theoretical calculations, the shape of physical bodies is not fundamental, it is assumed by default that it is spherical.
Why are the properties of bodies so important?
Physics itself as such arose from the need to comprehend the laws by which physical bodies behave, as well as the mechanisms of existence of various external phenomena. Natural factors include any changes in our environment that are not related to the results human activity. Many of them people use to their advantage, but others can be dangerous and even disastrous.
Research into behavior and different properties physical bodies is necessary for people in order to predict unfavorable factors and prevent or reduce the harm they cause. For example, by building breakwaters, people are accustomed to fighting negative manifestations sea elements. Humanity has learned to resist earthquakes by developing special earthquake-resistant building structures. The load-bearing parts of the car are made in a special, carefully calibrated shape to reduce damage in accidents.
About the structure of bodies
According to another definition, the term “physical body” implies everything that can be recognized as really existing. Any of them necessarily occupies part of the space, and the substances from which they consist are a collection of molecules of a certain structure. Its other, smaller particles are atoms, but each of them is not something indivisible and completely simple. The structure of an atom is quite complex. In its composition, one can distinguish positively and negatively charged elementary particles - ions.
The structure according to which such particles are arranged in a certain system is called crystalline for solids. Any crystal has a certain, strictly fixed shape, which indicates the ordered movement and interaction of its molecules and atoms. When the structure of crystals changes, the physical properties of the body are disrupted. It depends on the degree of mobility of the elementary components. state of aggregation, which can be solid, liquid or gas.
To characterize these complex phenomena, the concept of compression coefficients or volumetric elasticity, which are mutually inverse quantities, is used.
Molecular movement
A state of rest is not inherent in either atoms or molecules of solids. They are in constant motion, the nature of which depends on the thermal state of the body and the influences to which it is exposed. this moment exposed. Some elementary particles - negatively charged ions (called electrons) move at a higher speed than those with a positive charge.
From the point of view of the state of aggregation, physical bodies are solid objects, liquids or gases, which depends on the nature of molecular motion. The entire set of solids can be divided into crystalline and amorphous. The movement of particles in a crystal is recognized as completely ordered. In liquids, molecules move according to a completely different principle. They move from one group to another, which can be figuratively imagined like comets wandering from one celestial system to another.
In any gaseous body, the molecules have a much weaker bond than in liquid or solid ones. The particles there can be said to repel each other. The elasticity of physical bodies is determined by a combination of two main quantities - the shear coefficient and the coefficient of volumetric elasticity.
Fluidity of bodies
Despite all the significant differences between solid and liquid physical bodies, their properties have much in common. Some of them, called soft, occupy an intermediate state of aggregation between the first and second with physical properties inherent in both. A quality such as fluidity can be found in a solid (for example, ice or shoe polish). It is also inherent in metals, including fairly hard ones. Under pressure, most of them are capable of flowing like a liquid. By connecting and heating two solid pieces of metal, it is possible to solder them into a single whole. Moreover, the soldering process occurs at a temperature much lower than the melting point of each of them.
This process is possible provided that both parts are in complete contact. This is how various metal alloys are produced. The corresponding property is called diffusion.
About liquids and gases
Based on the results of numerous experiments, scientists have come to the following conclusion: solid physical bodies are not some isolated group. The difference between them and liquids is only in greater internal friction. The transition of substances into different states occurs under conditions of a certain temperature.
Gases differ from liquids and solids in that the elastic force does not increase even with a strong change in volume. The difference between liquids and solids is the occurrence of elastic forces in solids during shear, that is, a change in shape. This phenomenon is not observed in liquids, which can take any of the forms.
Crystalline and amorphous
As already mentioned, the two possible states of solids are amorphous and crystalline. Amorphous bodies include bodies that have the same physical properties in all directions. This quality is called isotropy. Examples include hardened resin, amber products, and glass. Their isotropy is the result of a random arrangement of molecules and atoms in the composition of the substance.
In the crystalline state, elementary particles are arranged in a strict order and exist in the form of an internal structure that periodically repeats in different directions. Physical properties Such bodies are different, but in parallel directions they coincide. This property inherent in crystals is called anisotropy. Its reason is the unequal strength of interaction between molecules and atoms in different directions.
Mono- and polycrystals
For single crystals internal structure homogeneous and repeated throughout the entire volume. Polycrystals look like many small crystallites chaotically fused with each other. The particles that make them up are located at a strictly defined distance from each other and within in the right order. A crystal lattice is understood as a set of nodes, that is, points that serve as the centers of molecules or atoms. Metals with a crystalline structure serve as materials for the frames of bridges, buildings and other durable structures. That is why the properties of crystalline bodies are carefully studied for practical purposes.
The actual strength characteristics are influenced by negative impact defects crystal lattice, both superficial and internal. A separate branch of physics, called solid mechanics, is devoted to similar properties of solids.
If I wanted to read, I haven't yet
knowing the letters, this would be nonsense.
In the same way, if I wanted to judge
about natural phenomena, without having any
ideas about the beginnings of things, this
it would be just as nonsense.
M. V. Lomonosov
Look around you. What a variety of objects surrounds you: people, animals, trees. This is a TV, a car, an apple, a stone, a light bulb, a pencil, etc. It is impossible to list everything. In physics any object is called a physical body.
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How are physical bodies different? A lot of people. For example, they can have different volumes and shapes. They can consist of different substances. Silver and gold spoons (Fig. 6) have the same volume and shape. But they consist of different substances: silver and gold. The wooden cube and ball (Fig. 7) have different volumes and shapes. These are different physical bodies, but made of the same substance - wood.
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In addition to physical bodies, there are also physical fields. Fields exist independently of us. They cannot always be detected using human senses. For example, the field around a magnet (Fig. 8), the field around a charged body (Fig. 9). But they are easy to detect using instruments.
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Various changes can occur with physical bodies and fields. A spoon dipped into hot tea heats up. The water in the puddle evaporates and freezes on a cold day. The lamp (Fig. 10) emits light, the girl and the dog are running (moving) (Fig. 11). The magnet becomes demagnetized and its magnetic field weakens. Heating, evaporation, freezing, radiation, movement, demagnetization, etc. - all these changes occurring with physical bodies and fields are called physical phenomena.
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By studying physics, you will become familiar with many physical phenomena.
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Physical quantities are introduced to describe the properties of physical bodies and physical phenomena. For example, you can describe the properties of a wooden ball and cube using physical quantities such as volume and mass. A physical phenomenon - movement (of a girl, a car, etc.) - can be described by knowing such physical quantities as path, speed, period of time. Pay attention to the main sign of a physical quantity: it can be measured using instruments or calculated using the formula. The volume of a body can be measured with a beaker of water (Fig. 12, a), or by measuring the length a, width b and height c with a ruler (Fig. 12, b), it can be calculated using the formula
V = a. b. c.
All physical quantities have units of measurement. You have heard about some units of measurement many times: kilogram, meter, second, volt, ampere, kilowatt, etc. You will become more familiar with physical quantities in the process of studying physics.
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Think and answer
- What is called the physical body? A physical phenomenon?
- What is the main sign of a physical quantity? Name the physical quantities known to you.
- From the above concepts, name those that relate to: a) physical bodies; b) physical phenomena; V) physical quantities: 1) drop; 2) heating; 3) length; 4) thunderstorm; 5) cube; 6) volume; 7) wind; 8) drowsiness; 9) temperature; 10) pencil; 11) period of time; 12) sunrise; 13) speed; 14) beauty.
Homework
We have a “measuring device” in our body. This is a heart with which you can measure (with not very high accuracy) a period of time. Determine by your pulse (the number of heartbeats) the time period for filling a glass with tap water. Consider the time of one blow to be approximately one second. Compare this time with the clock readings. How different are the results obtained?
In the minds of the average person, a strong opinion has been strengthened that with the moment of physical death, all biological processes in the body of the deceased stop, and his body gradually begins to decompose. In fact, this theory is far from the truth. After a person's heart stops beating and the brain loses control of the body, residual effects still occur in some parts of the body. physiological processes. 10 functions of the body that do not fade away after the death of a person will be discussed further.
10. Digestion
Who would have thought that when a person leaves this world, his digestive tract continues not only to expel digested food, but also to some extent to digest it. This is due to the fact that our body is inhabited by many microorganisms, some of which are an integral link in the mechanism of food digestion. When a person dies, the life of these bacteria does not stop, and they continue to actively fulfill their biological purpose. In addition, some of them are involved in the production of gas, thanks to which clumps of digested food can move through the dead intestines.
9. Erection and ejaculation
Abstractly speaking, the heart muscle is a physiological pump that pumps blood from one part of the body to another. When this organ stops performing its function, blood circulation stops, causing blood to accumulate in the lowest place of the body. If a person dies in a standing position or lying on his stomach, then it is not difficult to guess where most of his blood will collect. In addition, certain groups of muscle cells are activated by calcium ions after death. Thanks to this, after the actual occurrence of death, the onset of an erection followed by ejaculation is possible.
8. Nail and hair growth
It is difficult to put this function on a par with others given in this article, since it is rather external feature almost all dead bodies than really biological process, showing activity after the death of a person. Of course, non-living cells cannot reproduce either hair or nails, but after death the skin loses moisture, which is why it pulls back a little, exposing some part of the hair that was previously located in the thickness of the skin. At the same time, it visually creates the impression that the hair and nails of the deceased are actually growing.
7. Muscle movements
After brain death, some parts nervous system may remain active for some time. Scientists have more than once recorded the occurrence of reflexes in dead patients, in which an impulse went along the nerve fibers not to the brain, but to the spinal cord, due to which the deceased experienced muscle twitching or spasm.
6. Brain activity
In modern medicine, situations often occur when the brain has actually died, but the heart continues to function. The opposite and no less common situation is that when cardiac activity stops, the brain technically continues to live for a few more minutes. At this time, brain cells use all possible resources in order to seek out the oxygen and nutrients necessary to continue life. This short period, within which it is still possible to restore normal functioning of the brain, in our time it is quite possible to extend it up to several days with the help of certain drugs and with the necessary measures.
5. Urination
Many people think that the physiological act of passing urine is a completely voluntary action. However, this is not quite true. Our consciousness does not really control this mechanism - a certain area of the cerebral cortex is responsible for it. In addition, this zone takes an active part in regulating the respiratory system and cardiac activity. With rigor mortis, the muscles should seem to freeze, but this does not happen for some time after death. At the very moment of death, smooth and skeletal muscles relax, due to which the external urethral sphincter opens and, accordingly, urine flows out.
Drugs and alcohol have a depressing effect on the functioning of the area of the cerebral cortex responsible for urination. Therefore, people under the influence of these substances often experience involuntary loss of urine.
4. Skin cell growth
Oddly enough, but this function also does not fade away immediately after death. Skin cells, one of the few in human body, which do not require continuous blood supply. Therefore, from the moment cardiac activity stops, they continue to function and reproduce their own kind for some time.
3. Birth of a child
Documents have reached our time confirming that in the history of mankind there have been cases of so-called “posthumous birth”. The essence of this ritual is that if a woman died in late pregnancy, she was not buried until her body expelled the fetus. This mechanism is due to the accumulation of gases inside the body, which serve as a driving force leading the fetus through the birth canal.
2. Defecation
It is no secret to many of us that in moments of great excitement our body seeks to get rid of final products life activity. This happens because in a moment of stress, certain muscle groups suddenly relax, which causes a slight embarrassment. If we talk about the physical death of a person, then in this case the implementation of post-mortem defecation is facilitated not only by the relaxation of all muscles, but also by the increased production of gases in the intestines, which occurs as a result of the death of organic tissues. The passage of feces can occur several hours or a day after death.
1. Vocalization
This function is very sinister in nature, especially if you do not know the nature of this phenomenon. Rigor mortis affects almost all muscle groups, including those that functioned inside the vocal apparatus. Because of this, the dead body may produce soft sounds resembling groans or wheezing.
