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What determines the duration of the strike. Method for determining the duration of a stroke. Impact Biomechanics

Take a look at the dictionary of foreign words: "impulse" - from lat. impulsus - push, strike, motivation. " The effect produced by the blow has always been surprising in humans. Why is a heavy hammer laid on a piece of metal on the anvil only presses it against the support, and the same hammer crushes the metal with a hammer blow? And what is the secret of the old circus trick, when the crushing blow of a hammer on a massive anvil does no harm to the person on whose chest this anvil is installed? What is the mistake in the question that one student once asked: “What is the impact force when a load of 20 kg falls from a height of 10 m?” And what does the expression “impact force” mean?

Galileo was also interested in the problem of “amazing impact force”. He describes the witty experience with which he tried to determine the "power of the blow." The experiment consisted of the following: two buckets were suspended from one end, and a load (stone), balancing them, from one end to a solid beam mounted horizontally on an axis like a beam of a balance (Fig. 39). The upper bucket was filled with water; a hole closed by a cork was made in the bottom of this bucket.

If you remove the cork, then the water will pour into the lower bucket and the force of the impact of the jet on the bottom of this bucket, it would seem, will cause the right side of the rocker to fall. Adding the appropriate load on the left will restore equilibrium, and its mass will allow you to assess what the impact force of the jet is.

However, to Galileo's surprise, experience showed a completely different thing. At first, as soon as the cork was removed and the water began to pour out, not the right but the left part of the rocker arm fell. And only when the jet reached the bottom of the lower bucket, the balance was restored and was no longer disturbed until the end of the experiment.

How to explain this “strange” result? Is it wrong with Galileo's first assumption that a jet striking the bottom of the lower bucket will cause it to sink? To understand this rather complex issue, you need to know the law of conservation of momentum, which, together with the law of conservation of energy, refers to the greatest laws of nature.

The term “quantity of movement” was introduced by Galileo's contemporary, the French philosopher and mathematician Descartes, but it was introduced far from a scientific basis, but from metaphysical (not based on experience) religious ideas of the philosopher. The indefinite, foggy term “momentum” is now replaced by the term “momentum”.

In the previous conversation, we cited Newton’s second law in the form that Newton himself gave him: "The change in the momentum is proportional to the moving force and occurs in the direction of the straight line along which this force acts."

Newton first introduced the concept of mass into mechanics and, using it, gave an exact definition of the quantity of motion as the product of the mass of a body and its speed (mv).

If the initial speed v 0 of a body of mass m under the influence of any force during time t increases to v 1, then the change in momentum per unit time will be:

This change is proportional to the applied force F:

mv 1 - mv 0 \u003d Ft

This is Newton’s second law. It follows from it that the same change in the momentum can occur both with the prolonged action of a small force and with the short-term action of a large force. The product Ft can be considered as a measure of the force. It is called the impulse of power. Do not mix only the impulse of force with the force itself, as well as with the impulse. It can be seen from the above formula that the momentum of a force is not equal to the momentum itself, but to the change in momentum. In other words, the momentum of the force over time t is equal to the change in the momentum of the body during this time. Momentum is usually denoted by the letter p:

In the general case, it should be taken into account that the momentum is a vector physical quantity:

We have already mentioned the two greatest laws of nature: the law of conservation of momentum and the law of conservation of energy. These laws are conveniently demonstrated by the example of a blow. The phenomenon of shock is of great importance in science and technology. Consider this phenomenon more carefully.

We distinguish between elastic and inelastic materials. For example, a rubber ball is resilient; this means that after the termination of the deforming force (compression or tension), it again returns to its original form. On the contrary, a piece of clay crumpled by hand does not return to its original form. Rubber, steel, marble, bone are elastic materials. You can easily see the elasticity of the steel ball by dropping it from a certain height onto the elastic support. If the ball was previously smoked, then the trace will remain on the support not in the form of a point, but in the form of a sufficiently distinguishable speck, since the ball crumpled upon impact, although then, having rebounded, it regained its shape. The support is also deformed. The elastic force arising in this case acts on the ball from the support side and gradually reduces its speed, informing it of the acceleration directed upward. In this case, the direction of the speed of the ball changes to the opposite and it takes off above the support to the same height from which it fell (ideal case with perfect elasticity of the colliding bodies). The support itself, as connected with the Earth having a huge mass, practically remains motionless.

Successive changes in the shape of the ball and the surface of the support for different times are shown in Figure 40. The ball falls from a height h and at the time of landing (position in the figure) has a speed directed vertically downward. In position B, the deformation of the ball is maximum; at this moment, its speed is zero, and the force F acting on the ball from the side of the support plane is maximum: F \u003d F max. Then the force F begins to decrease, and the speed of the ball grows; point C corresponds to the moment when the speed value. In contrast to state A, now the speed is directed vertically upward, as a result of which the ball takes off (jumps) to a height h.

Suppose that an elastic ball moving at a certain speed collides with a stationary ball of the same mass. The action of a stationary ball is again reduced to a decrease in the speed of the first ball and its stopping. At the same time, the first ball, acting on the second, tells it the acceleration and increases its speed to its original speed. Describing this phenomenon, they say that the first ball transmitted its momentum to the second. You can easily verify this experimentally with two balls suspended on threads (Fig. 41). Measuring the speed with which the balls move is, of course, difficult. But you can use the well-known position that the speed acquired by the falling body depends on the height of incidence (). Except for small energy losses due to the incomplete elasticity of the balls, ball 2 will take off from the collision with ball 1 to the same height as ball 1 fell. Moreover, ball 1 will stop. The sum of the pulses of both balls, therefore, remains constant all the time.

It can be proved that the law of conservation of momentum is observed in the interaction of many bodies. If external bodies do not act on the system of bodies, then the interaction of bodies inside such a closed system cannot change its total momentum. You can now “scientifically” refute the boastful tales of Baron Munchausen, who claimed that he managed to pull himself out of the swamp by his own hair.

Returning to the famous Galileo experiment with which we began our conversation, we will not be surprised at the result of the experiment: in the absence of external forces, the momentum of the whole system could not change and therefore the beam remained in balance, despite the impact of the jet on the bottom of the second bucket. A detailed mathematical analysis of the experiment is rather complicated: it is necessary to calculate the decrease in mass of the upper bucket, from which the water jet pours out, the reaction of the leaky jet and, finally, the impulse reported to the bottom of the lower bucket by the impact of the jet. The calculation shows that the sum of all impulses, taking into account their signs, is equal to zero, as it was before the cork was pulled out, and the whole system — a beam, buckets, counterweight — remains in equilibrium.

The law of conservation of momentum and the law of conservation of energy are the basic laws of nature. Note, however, that the conservation of momentum in mechanical processes is always and unconditionally valid, while applying the law of conservation of energy in mechanics, one must be careful (it requires certain conditions to be satisfied). "Can not be! “You will exclaim indignantly,“ the law of conservation of energy is valid always and everywhere! ” And I don’t argue, read on. Let us consider an example of a collision of elastic and inelastic balls.

Bounce. Let a ball weighing 2 kg move at a speed of 10 m / s to hit a second (motionless) ball of the same mass. As we already know, after the impact, the first ball will stop, and the second will move at the speed of the first ball before the collision.

Check the law of conservation of momentum:

Law of energy conservation:

Both laws are observed.

Inelastic impact (balls made of soft clay or putty). After the impact, the stuck together balls continue to move together, but at a speed half that of the first ball before the impact.

The law of conservation of momentum:

The law is respected.

Law of energy conservation:

Before the impact, the energy was 100 J, and after the impact, 50 J! Where did half the energy go? You probably guessed: the mechanical energy equal to 50 J turned into internal energy: after the impact, the molecules began to move more briskly - the balls heated up. If we could take into account all types of energy before and after the impact, we would be convinced that even in the case of an inelastic impact, the energy conservation law is not violated. The law of conservation of energy is always true, but one must take into account the possibility of converting energy from one type to another. In practical cases, the application of the laws of conservation of energy and momentum is especially important. Consider a few examples of the application of these laws.

Forging products in the forge shop. The purpose of the forging is to change the shape of the product using hammer blows. For the best use of the kinetic energy of the falling hammer, it is necessary to put the product on a large anvil. Such an anvil will receive a negligible speed, and most of the energy upon impact will turn into deformation energy (the shape of the product will change).

Pile driving. In this case, it is advisable to transfer most of the kinetic energy to the pile so that it can do the job of overcoming the soil resistance and go deeper into the soil. The mass of the pile driver, i.e., the load that falls on the pile, must be greater than the mass of the pile. In accordance with the law of momentum, the pile speed will be higher in this case and the pile will go deeper into the ground.

On the power of impact. The task set at the beginning of our conversation does not indicate the duration of the strike, but the latter depends on the nature of the support. With rigid support, the duration of the impact will be less, and the average force of the impact is longer; with soft support, vice versa. The net, stretched under the trapezoid in the circus, protects the air gymnast from a strong blow when falling. A footballer, taking a hit of the ball, should be fed back, thereby increasing the duration of the strike - this will soften the kick. There are many such examples. In conclusion, we will examine another interesting problem, which after all of the above will be clear to you.

“Two boats move by inertia in the calm water of the lake towards each other in a parallel course at a speed of v 1 \u003d 6 m / s. When they caught up, the cargo was quickly transferred from the first boat to the second. After that, the second boat continued to move in the same direction, but with a speed of v 2 \u003d 4 m / s.

Determine the mass M 2 of the second boat if the mass M 1 of the first without a load is 500 kg and the mass m of the load is 60 kg. Calculate the energy reserve of boats and cargo before and after shifting the cargo. Explain why this energy reserve has changed. ”

Decision. Before meeting, the momentum of the first boat is: (M 1 + m) v 1, and the momentum of the second boat: M 2 v 1.

When transferring cargo from the first boat to the second, the speed of the first boat does not change, since it experiences a push in the lateral direction (recoil), which cannot overcome the resistance of water. The speed of the second boat changes, since the transferred cargo must sharply change the direction of its speed to the opposite, which can be considered as a push.

Applying the law of conservation of momentum, we write:

Energy decreased by 3500 J. Where did the energy go? The lost part of the mechanical energy turned into internal energy (heat) when the speeds of the load and the second boat were aligned.

Impact Strength - Impulse, Speed, Technique, and Explosive Force Exercises for Fighters

Release shot at the Leader-Sport fitness club

The organizer of the strike force tournament Puncher, master of sports in powerlifting, multiple champion and St. Petersburg bench press champion Pavel Badyrov continues to discuss the force of the blow, the speed of the blow, and also shows explosive strength exercises for fighters.

Hit

Impact is a short-term interaction of bodies in which redistribution of kinetic energy occurs. It is often destructive for interacting bodies. In physics, impact is understood as a type of interaction of moving bodies at which the interaction time can be neglected.

Physical abstraction

Upon impact, the law of conservation of momentum and the law of conservation of angular momentum are satisfied, but the law of conservation of mechanical energy is usually not satisfied. It is assumed that during the impact, the action of external forces can be neglected, then the total momentum of the bodies during the impact is preserved, otherwise it is necessary to take into account the momentum of external forces. Part of the energy usually goes to heating bodies and sound.

The result of a collision of two bodies can be fully calculated if their motion before the impact and mechanical energy after the impact are known. Usually either an absolutely elastic impact is considered, or the energy conservation coefficient k is introduced as the ratio of the kinetic energy after the impact to the kinetic energy before the impact when one body hits a fixed wall made of another body material. Thus, k is a characteristic of the material from which the bodies are made, and (presumably) does not depend on other parameters of the bodies (shape, speed, etc.).

How to understand the force of impact in kilograms

The momentum of a moving body is p \u003d mV.

When braking about an obstacle, this impulse is “quenched” by the impulse of the resistance force p \u003d Ft (the force is not constant at all, but you can take some average value).

We get that F \u003d mV / t is the force with which an obstacle slows down a moving body, and (according to Newton’s third law) a moving body acts on an obstacle, i.e., the impact force:
F \u003d mV / t, where t is the impact time.

A kilogram-force is simply an old unit of measure - 1 kgf (or kg) \u003d 9.8 N, i.e. this is a body weight of 1 kg.
To recalculate, it is enough to divide the force in Newtons by the acceleration of gravity.

ONCE AGAIN ABOUT STRIKE

The vast majority of people, even with higher technical education, vaguely imagine what impact force is and what it can depend on. Someone believes that the strength of the impact is determined by momentum or energy, and someone - by pressure. Some people confuse strong strikes with strokes that lead to injuries, while others believe that the force of the blow should be measured in units of pressure. Let's try to clarify this topic.

Impact force, like any other force, is measured in Newtons (N) and kilogram-forces (kgf). One Newton is a force due to which a body weighing 1 kg receives an acceleration of 1 m / s2. One kgf is a force that gives a body weighing 1 kg an acceleration of 1 g \u003d 9.81 m / s2 (g is the acceleration of gravity). Therefore, 1 kgf \u003d 9.81 N. The weight of a body of mass m is determined by the attractive force P, with which it presses on the support: P \u003d mg. If your body weight is 80 kg, then your weight, determined by gravity or gravity, P \u003d 80 kgf. But in vernacular they say "my weight is 80 kg", and everyone understands everything. Therefore, it is often said about the strength of the impact that it amounts to some kg, but kgs is implied.

Impact force, in contrast to gravity, is quite short-lived in time. The shape of the shock pulse (in simple collisions) is bell-shaped and symmetrical. In the case of a person hitting a target, the pulse shape is not symmetrical - it increases sharply and falls relatively slowly and wave-like. The total pulse duration is determined by the mass enclosed in the shock, and the pulse rise time is determined by the mass of the shock limb. When we talk about impact force, we always mean not the average, but its maximum value in the process of impact.

We’ll not throw the glass into the wall so that it breaks. If he got into the carpet, he might not crash. In order for it to break for sure, it is necessary to increase the throwing force in order to increase the speed of the glass. In the case of the wall, the blow turned out to be stronger, since the wall is tougher, and therefore the glass broke. As we see, the force acting on the glass turned out to depend not only on the strength of your throw, but also on the stiffness of the place where the glass fell.

So is the blow of man. We only throw our hand and the part of the body involved in the strike into the target. Studies have shown (see "Physics and Mathematics Model of Impact") that the part of the body participating in the impact has little effect on the force of the impact, since its speed is very low, although this mass is significant (it reaches half the body weight). But the force of the impact was proportional to this mass. The conclusion is simple: the impact force depends on the mass participating in the impact, only indirectly, since with the help of just this mass, our shock limb (arm or leg) is accelerated to maximum speeds. Also, do not forget that the momentum and energy imparted to the target upon impact are mainly determined by this mass (by 50–70%).

Back to the force of the blow. The impact force (F) ultimately depends on the mass (m), dimensions (S) and speed (v) of the impact limb, as well as on the mass (M) and stiffness (K) of the target. The basic formula for the force of impact on an elastic target:

It can be seen from the formula that the lighter the target (bag), the lower the impact force. For a bag weighing 20 kg compared with a bag of 100 kg, the impact force is reduced by only 10%. But for bags of 6–8 kg, the impact force already drops by 25–30%. It is clear that, hitting the balloon, we will not get any significant value at all.

The following information you will have to mostly take for granted.

1. A direct hit is not the most powerful of the blows, although it requires a good technique of execution and especially a sense of distance. Although there are athletes who do not know how to beat the side, but, as a rule, a direct blow is very strong.

2. The force of a side impact due to the speed of the shock limb is always higher than the direct one. Moreover, with the delivered impact, this difference reaches 30-50%. Therefore, side impacts are usually the most knockout.

3. Swipe swipe (such as a backfist with a turn) - the easiest in terms of performance technique and does not require good physical preparation, practically the most powerful among hand strokes, especially if the striker is in good physical shape. It’s only necessary to understand that its strength is determined by a large contact surface, which is easily achievable on a soft bag, and in a real battle for the same reason, when striking a hard complex surface, the contact area is greatly reduced, the impact force drops sharply, and it is not very effective. Therefore, in battle it requires even higher accuracy, which is not at all easy to implement.

We emphasize once again that the blows were examined from a position of strength, moreover, against the soft and large bag, and not according to the size of the damage inflicted.

Shell gloves weaken blows by 3–7%.

Gloves used for competitions weaken strikes by 15–25%.

For reference, the results of measurements of the strength of the delivered blows should be as follows:

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# boxing lessons

Impact force - impulse, speed, technique and explosive force exercises for fighters from Pavel Badyrov updated: January 6, 2018 Posted by: Boxingguru

MECHANICAL SHOCK

Nizhny Novgorod
year 2013

Laboratory work No. 1-21

Mechanical shock

purpose of work: Get familiar with the elements of the theory of mechanical shock and experimentally determine the impact time, the average impact force Frecovery factor E, as well as study the basic characteristics of the impact and familiarize yourself with digital instruments for measuring time intervals.

Theoretical part

Impact is called a change in the state of movement of the body, due to its short-term interaction with another body. During impact, both bodies undergo shape changes (deformation). The essence of elastic shock lies in the fact that the kinetic energy of the relative motion of colliding bodies, in a short time, is converted into the energy of elastic deformation or, to one degree or another, into the energy of molecular motion. In the process of impact, energy is redistributed between colliding bodies.

Let a ball with a certain speed V 1 fall on a flat surface of a massive plate and bounce off it with a speed V 2.

We denote Are the normal and tangential components of the velocities and, and, and are the angles of incidence and reflection, respectively. In the ideal case, with absolutely elastic impact, the normal components of the rates of incidence and reflection and their tangential components would be equal; . Upon impact, a partial loss of mechanical energy always occurs. The ratio of both normal and tangential velocity components after impact to velocity components before impact is a physical characteristic that depends on the nature of the colliding bodies.

This characteristic Ecalled the recovery coefficient. Its numerical value lies between 0 and 1.

Determination of average impact force,

Initial and final ball velocities upon impact

The experimental setup consists of a steel ball A suspended on conductive threads and a motionless body B of a larger mass with which the ball collides. Suspension angle α is measured on a scale. At the moment of impact, a ball of mass m is affected by gravity from the side of the Earth, the reaction force from the side of the thread, and the average force of impact from the side of body B (see Fig. 2.).

Based on the theorem on the change in momentum of a material point:

where and are the velocity vectors of the ball before and after the impact; τ is the duration of the impact.

After designing equation (2) on the horizontal axis, we determine the average impact force:

(3)

Ball speeds V 1 and V 2 are determined on the basis of the law of conservation and conversion of energy. The change in the mechanical energy of the system formed by the ball and the stationary body B in the Earth's gravitational field is determined by the total work of all external and internal non-potential forces. Since the external force is perpendicular to the movement and the thread is inextensible, this force does not work, the external force and the internal force of the elastic interaction are potential. If these forces are much larger than other non-potential forces, then the total mechanical energy of the selected system does not change. Therefore, the energy balance equation can be written as:

(4)

From the drawing (Fig. 2) it follows that , then from equation (4) we obtain the values \u200b\u200bof the initial V 1 and final V 2 ball speeds:

(5)

where and are the angles of deflection of the ball before and after the collision.

Method for determining the duration of an impact

In this paper, the duration of a ball hitting a plate is determined by the frequency meter Ch3-54, the functional diagram of which is shown in Fig. 3. From the generator, pulses with a period T are fed to the input of the control system of the control system. When during the collision of the metal plate B, the electric circuit formed by the control system, the conductive ball suspension threads, the ball, the plate B and the pulse counter C h, turns out to be closed, and the control system passes at the counter input C h, electric current pulses only in the time interval equal to the duration of the shock. The number of pulses recorded during the time is equal to where.

To determine the duration of the impact, it is necessary to multiply the number of pulses recorded by the counter by the period of pulses taken from generator G.

experimental part

Initial data:

1. The mass of the ball m \u003d (16.7 ± 0.1) * 10 -3 kg.

2. Thread length l \u003d 0.31 ± 0.01 m.

3. Acceleration of gravity g \u003d (9.81 ± 0.005) m / s 2.

4. Experience for each corner is performed 5 times.

The results of the experiment are listed in the table:

№	α 1 \u003d 20 0	α 1 \u003d 30 0	α 1 \u003d 40 0	α 1 \u003d 50 0	α 1 \u003d 60 0
i	2i	i	2i	i	2i	i	2i	i	2i
	61,9	17,1	58,0	26,8	54,9	37,0	52,4	43,6	48,9	57,8
	65,7	17,2	58,2	26,5	45,2	35,9	51,0	45,0	42,6	58,0
	64,0	16,9	58,4	26,9	52,8	36,7	49,9	46,7	49,6	57,2
	65,4	16,8	58,4	26,7	54,3	36,0	48,2	46,0	48,5	57,6
	64,0	16,9	57,3	26,8	52,4	37,0	50,2	43,9	48,4	58,1
Wednesday	64,2	16,98	58,06	26,74	51,92	36,52	50,34	45,04	47,6	57,74

Calculations

=20 0 μs

=30 0 μs

=40 0 μs

Pulse - health, life expectancy, aging and immortality.

Pulse is a shock in the blood vessels from strokes.of our heart, and the size and nature of the work, all our life depends on them, as on the main pendulum, life expectancy, health, aging and immortality are determined. Heart rate and heart size givelife speed its duration and aging. The heart of living organisms, perfect and accuratetime mechanisms and meters speed of life.For thousands of years, people have tried to reproduce the unique accuracy and capabilities of the heart in the form of a water, hourglass, or mechanical clock.Information encoded andbuilt into genes chromosomes, organisms and populations, on the intensity and level of work on which prosperity depends,life expectancy and their service life.

3 the dependence of the nature of the pulse and the work of the heart on the impulse, stimulus, or conditions formed the basispulse diagnostics,determining and managing the state of the body, sports prospects, reproductive properties, tone depth and possible life expectancy.

Normal heart rate a healthy person should be 65-75 beats. in min., its level for average weight should not change, the aging rate and life expectancy of 25 and 100 years, depend on the optimal and harmonious pulse. The heart rate of a person at rest, it happens from 30 to 200 beats. in minutes and more, changes weight, age, time of day, fitness, habits and lifestyle. The heartbeat frequency and the size of the heart, change the disease of a person and the body, a lower pulse with bradycardia, increases the heart, and an increased pulse with tachycardia, reduces the size.

Heart rate and nature indicate the amount of health physical state and size - this is strength, speed, endurance and weight - growth characteristics of the body. Birds and animals at home live much more than their free counterparts in nature, sometimes this difference is different at times, their metabolic rate changes and decreases and their size grows.

Flight Caliber Pulse for example it is 1,200 beats per minute, alone 500 beats, and in the cordon only 50 beats. And the crocodile pulse normally makes 25-40 beats per minute, and in a state of stupor 1-5 beats, depending on the mass.Calibri live 1–2 years, some species up to 9 years old, crocodiles 5–8 years old, some species can live up to 100 years, and whales live 30–50 years, some species of whales up to 200 years or more.

The biochemistry of the body and the work of organs change already seconds after exposure, and the pulse changes its work after a fraction of a second, changing proportions of substances and health, priorities and nature of adaptation,level of aging and futurelife expectancy or immortality.

Due to changes in the so-called variability, different species can reduce energy expenditures when changing external conditions and environments, showing records of endurance and speed in the struggle for survival. A crocodile can do without food for a year or more, and young antelopes and gazelles compete in speed with a cheetah in a few days and even hours after birth.

Of course, a person could not do without food for months and even more so a year, like a crocodile, but reaction and adaptation can also vary widely, asheart rate fluctuationswherein. So, when cooling, the pulse slows down, and when doing work or a disease, it increases sharply. The stronger these fluctuations, the usually the higher the depth of the body tone and the level of metabolism.

Life expectancy depends on the genes of a particular organism, heart rate, and metabolic rate. The greater the mass of the type of organism, the higher the life expectancy; it is noticed that the lower the natural temperature of the organism, the higher it is. It is enough to lower the temperature by one and a half to two degrees, from the natural temperature of 36.6 degrees, to a person with an optimal weight, this will reduce aging and increase life expectancy by tens of years or more. It is worth making a reservation, each species has its own optimal mass. For peopledepending on gender and height,it is from 55 to 85 kilograms, going beyond these limits reduces life expectancy.

Objectively, any excess over 60 kilograms is already a drawback, and the difference in average weight, which depends on gender, should not exceed 20 - 25 kg. It is noticed that people whose weight and height are lower, they have less background of nerve diseases, cancer, diabetes and so on, which is associated with better functioning of the immune system and higher quality of tissues and the level of regeneration that fall with increasing weight.

High human life expectancy at an average of 70 - 80 years, and in other cases up to 100 years or more. The slow pace of aging compared to animals is a payment for the loss of metabolic rate. As a result, we suffer from diseases, many of which are not in the animal kingdom and must be put up with a long period of restoration of the functions of organs and the body after diseases, injuries and work. For example, some insects will repair damage incompatible with life in half an hour, and a torn flower of a plant can go through a full cycle to form full seeds, which is not given to humans. A person is forced to care for his children up to 18-20 years or more until they are fully adapted to an independent life, this is the period by which all the main animal species are already completing their life cycle.

You need to understand that the main regulators are in our brain, these are small departments - the thymus, pineal gland and the most important hypothalamus, from which all our functions, including the pulse, depend. These are the organs on the work of which the production of hormones of youth and life depends, especially the most important of them is the gonadotropin hormone, known as growth hormone.The pineal gland produces melatonin and serotonin. Melotonin sets the sleep, rest and life span, and serotonin is responsible for physical growth and good mood. The more hormones per unit mass, the higher the level of health, and a drop in their values \u200b\u200bleads to illness, impairing the management of organs and tissues. This is a common situation, the occurrence and development of cancer, a decrease in tissue quality, when the body's health is measured by the weakest or worst organ.

Known for the production of hormones, during sleep the temperature of the human body falls,and the pulse rate in the REM stage is growing, we can conclude - life expectancy depends on the quantity and quality of sleep. By increasing the duration and quality of sleep, you can control the production of hormones, the growth of life expectancy and other processes and functions of the body.

In nature, animals fall into a stupor and prolonged sleep, having found complete safety, stable and comfortable conditions, deep in the ground or on the ceiling of caves and far from the action of the sun.In extreme cases, due to the shadow high on the tree, providing the body with extreme relaxation and the prototype of the necessary biochemistry, reducing the pulse. It turns out that animals turn the worst environmental conditions into the greatest advantage, that is, into the production of harmonies, turning into a stupor or a prolonged sleep and losing weight.

The most interesting thing is that sometimes people in some situations also fall into a prolonged sleep, and even in a stupor ceasing to grow old, there are numerous cases of litargic sleep and even a case of stupor.Hamba lama He entered this state in 1927, according to his will in 2002 he was pulled out of the grave when he was 160 years old and breathing, the horse beat with a frequency of 2 beats per minute, and the biological age, according to scientists, was 75 years. Now he most likely died due to the fact that there is no one to help him get out of suspended animation, because for various reasons none of hisstudents and followers.

Giving our body relaxation, comfort and ideal biochemistry, stimulating the production or introducing ready-made hormones, you can get an increase in life expectancy, changing the pulse in accordance with external influences in the phase and interests of the body, essentially reproducing the macropulos remedy.

Scientists have noticed that a high IQ - level of intelligence is the key to high life expectancy, so the ownersIQ - 85 live up to 80 years, and withIQ - 115 live more than 100 years, explain this by higher stress resistance of people with higher intelligence. But most likely he is tallIQ and high life expectancy are interconnected by a feature of genetics, a type of biochemistry, and characteristics of the heart and pulse.

Statistics show that it is precisely nervous and overexcited people who often get sick and shorten their lives due to depletion of reserves of the most valuable components of the body. For the population, the favorable environment is important, the harder the external conditions, the shorter the period between generations. So with the advent of comfortable conditions, the average life expectancy of people has tripled.

There is a clear relationship between performance, productivity, reproduction on the one hand, and life expectancy on the other. Higher any component of the first partand the higher the pulse or less body weight,the lower the life expectancy. Reproductivity occupies a special place in life expectancy, which may be why the gods, who lived in myths forever, but could not have children.

It is necessary to pay attention to the fact that each type of living organism, including ours, has its own optimal pulse and mass values, going beyond the pedals of which causes various diseases and a reduction in life expectancy. It’s not a secret that people whose height is more than 195 centimeters live 30–50 years, that is, significantly less than those whose height is less than 180 centimeters, who live 60–100 years, and sometimes more.

One of the innermost desires of any person to live forever, in connection with these aspirations, great minds, experienced specialists and alchemists have been searching for the elixir or code of immortality for thousands of years. Recently, this search has led to an inconspicuous microscopic subspecies of the jellyfish of the turinopsis nutricule with a size of only 5 millimeters. It turned out that they are truly immortal and able to live a thousand years. And the code of immortality or youth is contained in the biochemistry of their body. They are able to regain youth by injecting some substance after reproduction and reaching a certain limit of biorhythms. From this moment, rejuvenation begins, turning in the opposite direction from the adult state to the larval form, reaching the stage of the larval polyp, again towards the adult organism. This continues as many times as you like, but practically forever, if they are not physically destroyed, for example, by a predator.

To increase life expectancy and the necessary biochemistry with a pulse of one to two beats per minute, it is more correct to enter the body into a trance or numbness instead of freezing it and damaging the cells. Given that in a limited space you can create virtually any conditions that are thousands or millions of times different in magnitude from external influences, the nature of sleep or numbness can also be created quite comfortable and harmonious for a particular organism. This is extremely important when flying outside the solar system, where it is necessary to maintain the internal constancy of biochemistry, where the background of calcium and potassium is especially important, but there are also mass restrictions when cryostations are unacceptable luxury.

It is only necessary to recreate the conditions in order to achieve eternal youth and immortality.

Since time immemorial, people have been racking their brains for what megalithic dolmens were intended for. And all in similar features describe their structure, these are usually four stone stones, carefully adjusted to each other, one of which has a hole, and is covered with a fifth stone on top. All together sometimes with the sixth stone intended for the floor, it forms a room with a carefully fitted stopper covering the hole.

The conclusion is that the person who got inside, and the more so having closed the plug, was going to fence off something. From what? In this version, one is the most suitable conclusion from external influences, and first of all from the sun, as high-precision instruments are placed deep underground to raise their sensitivity.Dalmens most likely -it is a kind of sanctuary to achieve enlightenmentand a trance with a pulse of several beats per minute, where everyone, depending on what his brain was imprisoned for, could receive his innermost.

The cells in the monasteries’s monasteries are designed for the same purpose, only 10,000 years ago people came to this, more thoroughly and monumentally, given the interactions of nature, a living organism and the laws of physics. In this design, the buildings and the Krasnodar dolmens, without fail, made it possible to increase the sensitivity and prepare the brain for entering into a trance. For example, to communicate with the spirits of the dead, they were connected to the information field, which allowed proscopy and retroscopy to see the future and the past. In addition, they just turned offfrom earthly problems and past to fully relax and start a new life.

Our ancestors gave dolmens, a method and a device for the shortest way, achieving harmony and perfection, and we need to restore the “technique” and “school” ourselves.

An attempt to analyze the trauma of blows to the head with a bare fist, compared with punches in a boxing glove.

Shock theory.

A shock in mechanics is a short-term interaction of bodies, as a result of which their velocities change. Impact force depends, according to Newton's law, on the effective mass of the striking body and its acceleration:

Fig. 1 Impact force development curve over time

F \u003d m * a (1),

where
F is power
m is the mass
a is the acceleration.

If we consider the impact in time, then the interaction lasts a very short time - from ten thousandths (instantaneous quasi-elastic impacts) to tenths of a second (inelastic impacts). The shock force at the beginning of the impact increases rapidly to the highest value, and then drops to zero (Fig. 1). Its maximum value can be very large. However, the main measure of the impact interaction is not the force, but the impact pulse, numerically equal to the area under the curve F (t). It can be calculated as an integral:

(2)

where
S is the shock pulse,
t1 and t2 - time of the beginning and end of the impact,
F (t) is the dependence of the shock force F on time t.

Since the collision process lasts a very short time, in our case it can be considered as an instantaneous change in the velocities of the colliding bodies.

In the process of impact, as in any natural phenomena, the law of conservation of energy must be observed. Therefore, it is natural to write the following equation:

E1 + E2 \u003d E’1 + E’2 + E1p + E2p (3)

where
E1 and E2 are the kinetic energies of the first and second bodies before impact,
E’1 and E’2 are kinetic energies after impact,
E1p and E2p are the energy of impact loss in the first and second bodiese.

The relationship between kinetic energy after impact and loss energy is one of the main problems of impact theory.

The sequence of mechanical phenomena upon impact is such that first the deformation of the bodies occurs, during which the kinetic energy of the motion passes into the potential energy of elastic deformation. Then the potential energy goes back to kinetic. Three types of impact are distinguished depending on which part of the potential energy goes into kinetic and which is lost, dissipated by heating and deformation:

Absolutely resilient punch - all mechanical energy is conserved. This is an idealized model of collision, however, in some cases, for example, in the case of billiard balls, the picture of collision is close to absolutely elastic impact.
Absolutely Inelastic Impact - the energy of deformation is completely converted into heat. Example: landing in jumps and bounces, hitting a ball from plasticine into a wall, etc. With an absolutely inelastic impact, the velocities of the interacting bodies after the impact are equal (the bodies stick together).
Partially Inelastic Impact - part of the energy of elastic deformation passes into the kinetic energy of motion.

In reality, all impacts are either absolutely or partially inelastic. Newton proposed characterizing the inelastic impact by the so-called recovery coefficient. It is equal to the ratio of the velocities of the interacting bodies after and before the impact. The smaller this coefficient, the more energy is spent on the non-kinetic components E1p and E2p (heating, deformation). Theoretically, this coefficient cannot be obtained, it is determined empirically and can be calculated by the following formula:

where
v1, v2 - the speed of the bodies before the impact,
v’1, v’2 - after the strike.

At k \u003d 0, the impact will be absolutely inelastic, and at k \u003d 1 - absolutely elastic. The recovery coefficient depends on the elastic properties of the colliding bodies. For example, it will be different when a tennis ball hits different soils and rackets of different types and qualities. The recovery coefficient is not just a characteristic of the material, since it also depends on the speed of impact interaction - with an increase in speed, it decreases. The directories give values \u200b\u200bof the recovery coefficient for some materials for an impact velocity of less than 3 m / s.

Impact Biomechanics

Percussion in biomechanics refers to actions whose result is achieved by mechanical shock. In percussion actions distinguish:

Swing - the movement preceding the shock movement and leading to an increase in the distance between the shock link of the body and the object to strike. This phase is the most variable.
Shock motion - from the end of the swing to the start of the strike.
Impact interaction (or actually impact) - collision of impacting bodies.
Aftershock- the movement of the shock link of the body after the termination of contact with the subject, which struck.

With a mechanical impact, the speed of the body (for example, the ball) after the impact is higher, the higher the speed of the impacting link immediately before the impact. For strikes in sports, such a relationship is optional. For example, when serving in tennis, an increase in the speed of movement of the racket can lead to a decrease in the speed of departure of the ball, since the impact mass during strokes performed by an athlete is variable: it depends on the coordination of his movements. If, for example, a strike is performed by bending the hand or with a relaxed hand, then only the mass of the racket and hand will interact with the ball. If, at the moment of impact, the striking link is fixed by the activity of antagonist muscles and is, as it were, a single solid, then the mass of this link will take part in the shock interaction.

Sometimes an athlete strikes two blows at the same speed, and the ball’s relegation speed or impact force is different. This is due to the fact that the shock mass is not the same. The magnitude of the impact mass can be used as a criterion for the effectiveness of the impact technique. Since it is rather difficult to calculate the impact mass, the impact interaction efficiency is estimated as the ratio of the velocity of the projectile after impact and the velocity of the impact element before impact. This indicator is different in strokes of different types. For example, in football, it varies from 1.20 to 1.65. It depends on the weight of the athlete.

Some athletes who possess a very strong blow (in boxing, volleyball, football, etc.) do not differ in great muscle strength. But they are able to communicate greater speed to the striking segment and, at the moment of impact, interact with the striking body by a large shock mass.

Many percussive sports actions cannot be considered as a “pure” kick, the basis of the theory of which is described above. In the theory of impact in mechanics, it is assumed that the impact occurs so quickly and the impact forces are so great that all other forces can be neglected. In many shock actions in sports, these assumptions are not justified. The impact time in them, although short, is nevertheless impossible to neglect; the impact interaction path, along which colliding bodies move together during the impact, can reach 20-30 cm.

Therefore, in sports shock actions, in principle, it is possible to change the amount of movement during a collision due to the action of forces not related to the impact itself. If the shock link during acceleration is additionally accelerated due to muscle activity, the shock momentum and, accordingly, the projectile departure speed increase; if it is arbitrarily braked, the shock pulse and the departure speed decrease (this is necessary for accurate shortened strokes, for example, when passing the ball to a partner). Some shock movements, in which the additional increase in momentum during a collision is very large, are generally a cross between throwing and striking (this is how they sometimes perform second gear in volleyball).

The coordination of movements with the most severe impacts obeys two requirements:

the message of the highest speed to the striking link at the moment of contact with the striking body. In this phase of movement, the same methods of increasing speed are used as in other moving actions;
increase in shock mass at the time of impact. This is achieved by “fixing” the individual links of the striking segment by simultaneously activating the antagonist muscles and increasing the radius of rotation. For example, in boxing and karate, the power of the blow with the right hand is approximately doubled if the axis of rotation passes near the left shoulder joint, compared with strokes in which the axis of rotation coincides with the central longitudinal axis of the body.

The impact time is so short that it is already impossible to correct the mistakes made. Therefore, the accuracy of the strike is decisively ensured by the correct actions during the swing and shock movement. For example, in football, the place of setting the supporting leg determines for beginners the target accuracy of about 60-80%.

Tactics of sports often require strikes that are unexpected for the enemy (“hidden”). This is achieved by performing strokes without preparation (sometimes even without a swing), after fraudulent movements (feints), etc. The biomechanical characteristics of strokes change, since they are performed in such cases usually due to the action of only distal segments (wrist strokes).

Distal - [e.g. end, phalanx] (distalis) - the end of a muscle or bone of a limb or the whole structure (phalanx, muscle) farthest from the body.

A kick in a boxing glove and without.

Recently, in some sports circles, serious debate has flared up over more traumatic brain injuries in a boxing glove than blows with a bare hand. We will try to get an answer to this question using the available research data and elementary laws of physics.

Where could such thoughts come from? I dare to suggest that it is mainly from observations of the process of hitting a boxing bag. Studies were conducted in which Smith and Hemil, in his 1986 paper, measured the athlete’s fist speed and the speed of a boxing bag. Strictly speaking, the risk of concussion is determined by the magnitude of head acceleration, not speed. However, the reported speed of the bag can only indirectly judge the magnitude of the acceleration, because it is assumed that this speed was developed over a short period of time impact.

Blows on the bag were carried out in three different ways: with a bare fist, in a glove for karate and in a glove for boxing. Indeed, the speed of the bag when hit with a glove was about 15% higher than when hit with a fist. Consider the physical background of the study. As mentioned above, all impacts are partially inelastic and part of the energy of the shock element is spent on the permanent deformation of the projectile, the rest of the energy is spent on communicating kinetic energy to the projectile. A fraction of this energy is characterized by a recovery coefficient.

For the sake of clarity, we immediately make a reservation that when considering the strain energy and the energy of translational motion, the large strain energy plays a positive role, since less translational energy remains. In this case, we are talking about elastic deformations that are not dangerous to health, while the energy of translational motion is directly related to acceleration and is dangerous to the brain.

We calculate the recovery coefficient of the boxing bag according to the data obtained by Smith and Hemil. The mass of the bag was 33 kg. The experimental results showed insignificant differences in fist speed for different types of gloves (bare fist: 11.03 ± 1.96 m / s, in a karate glove: 11.89 ± 2.10 m / s, in a boxing glove: 11.57 ± 3.43 m / s). The average fist velocity was 11.5 m / s. Differences in bag momentum were found for different types of gloves. A blow in a boxing glove caused a greater impulse of the bag (53.73 ± 15.35 N s) than a blow with a bare fist (46.4 ± 17.40 N s) or in a karate glove (42.0 ± 18.7 N s), which had almost equal values. To determine the speed of the bag by its momentum, you need to divide the momentum of the bag by its mass:

v \u003d p / m (5)

where
v is the speed of the bag,
p is the momentum of the bag,
m is the mass of the bag.

Using the formula for calculating the recovery coefficient (4) and assuming that the speed of the fist after the impact is zero, we obtain a value for hitting with a bare fist of about 0.12, i.e. k \u003d 12%. For the case of a hit with a boxing glove, k \u003d 14%. This is confirmed by our life experience - a blow to a boxing bag is almost completely inelastic and almost all of the impact energy is spent on its deformation.

It should be noted separately that the fist had the highest speed in a karate glove. The momentum of the bag when it was hit by a karate glove was the smallest. Bare punch rates in this study were intermediate. This can be explained by the fact that the athletes were afraid to hurt the arm and reflexively reduced the speed and power of the blow. When struck in the karate glove, such fear did not arise.

And what will happen when hit in the head? Let us turn to another study of Valilko, Viano, and Bira for 2005, in which boxing gloves with gloves were studied on a specially designed dummy (Fig. 2). In this paper, all impact parameters and impact on the mannequin's head and neck were investigated in detail. The neck of the mannequin was an elastic metal spring, so this model can be considered as a model of a boxer ready to hit with tight neck muscles. We will use the data on the forward movement of the dummy’s head and calculate the recovery coefficient (k) for a direct hit to the head.

Fig. 2 Exploration of Valilco, Viano and Bira - a boxer strikes a dummy.

The average speed of the hand before impact was 9.14 m / s, and the average speed of the head after impact was 2.97 m / s. Thus, according to the same formula (4), the recovery coefficient k \u003d 32%. This means that 32% of the energy went into the kinetic movement of the head, and 68% went into the deformation of the neck and gloves. Speaking of neck strain energy, this is not about geometric deformation (curvature) of the cervical spine, but about the energy expended by the neck muscles (in this case, the spring) to keep the head stationary. In fact, this is the energy of resistance to shock. On the deformation of the face of the mannequin, as well as the facial skull of a person, there can be no question. Human bones are very strong material. In the table. Figure 1 shows the coefficient of elasticity (Young's modulus) of several materials. The larger this coefficient, the stiffer the material. The table shows that in terms of stiffness, the bone is slightly inferior to concrete.

Table 1. Elastic coefficients (Young's moduli) of different materials.

What will be the recovery coefficient for a blow to the head with a bare fist? There are no studies on this subject. But let's try to figure out the possible consequences. When struck with a fist, just like with a glove, most of the energy will be taken over by the muscles of the neck, provided, of course, that they are tense. In the work of Valilko, Viano and Bira, it is impossible to separate the energy of deformation of the glove from the energy of deformation of the neck of a mannequin, but it can be assumed that the lion's share of the total energy of deformation went into neck deformation. Therefore, it can be considered that when struck with a bare fist, the difference in the recovery coefficient will not exceed 2-5% compared to a gloved blow, as was the case in Smith and Hemil, where the difference was 2%. Obviously, a 2% difference is not significant.

The above calculations were made on the basis of data on the linear acceleration of the head after an impact. But for all their relative complexity, they are very far from predicting the invasiveness of the impact. The English physicist Holborn, who worked with gel models of the brain in 1943, was one of the first to put forward rotational acceleration of the head as the main parameter of brain injury. In the work of Ommaya et al., It is stated that a rotational acceleration of 4,500 rad / s2 leads to concussion and serious axonal injuries. An earlier work by the same author states that rotational acceleration above 1800 rad / s2 creates a 50% chance of concussion. The article by Valilko, Viano and Bira gives the parameters of 18 different strokes. If you take the same boxer and his punch at a speed of 9.5 m / s and a punch at a speed of 6.7 m / s, then in the first case, the recovery coefficient is 32%, and in the second it is 49%. According to all our calculations, it turns out that the second blow is more traumatic: a larger recovery coefficient (more energy went into the translational movement of the head), a large effective mass (2.1 kg and 4.4 kg), a slightly larger head acceleration (67 g and 68 g ) However, if we compare the rotational acceleration of the head produced by these two strokes, we will see that the first blow is more traumatic (7723 rad / s2 and 5209 rad / s2, respectively). Moreover, the difference in numbers is quite significant. This fact indicates that the impact morbidity depends on a large number of variables and it is impossible to be guided by only one impulse p \u003d mv, evaluating the impact efficiency. The place of impact plays a great role here, so as to cause the greatest rotation of the head. In connection with the above data, it turns out that the factor of the boxing glove in injuries and concussions does not play a major role.

To summarize our article, we note the following. The factors affecting brain injuries during a hit in a boxing glove and without it do not differ significantly and can change in one direction or the other, depending on the boxer and the type of impact. Much more significant factors affecting concussion lie outside the plane under consideration, such as the type and place of the blow to the head, which determines its rotational moment.

At the same time, one should not forget that boxing gloves are designed primarily to protect the soft tissues of the face. Hitting without gloves leads to damage to the bones, joints and soft tissues of both the attacker and the attacked athlete. The most common and painful of these is an injury called a “boxer knuckle”.

Boxer knuckle is a term known in sports medicine used to describe a hand injury - damage to the joint capsule of the metacarpophalangeal joint (usually II or III), namely the fibers that hold the tendon of the extensor muscle of the fingers.

The danger of infection with various infections, including hepatitis C or HIV viruses and a host of other unpleasant consequences, including an unattractive appearance, in every possible way reject the thesis that fighting with bare hands is safer for health.

References:

1. Lamash B.E. Lectures on biomechanics. https://www.dvgu.ru/meteo/book/BioMechan.htm
2. Smith PK, Hamill J. The effect of punching glove type and skill level on momentum transfer. 1986, J. Hum. Mov. Stud. vol. 12, pp. 153-161.
3. Walilko T.J., Viano D.C. and Bir C.A. Biomechanics of the head for Olympic boxer punches to the face. 2005, Br J Sports Med. vol. 39, pp. 710-719
4. Holbourn A.H.S. Mechanics of head injury. 1943, Lancet. vol. 2, pp. 438-441.
5. Ommaya A.K., Goldsmith W., Thibault L. Biomechanics and neuropathology of adult and pediatric head injury. 2002, Br J Neurosurg. vol.16, No. 3, pp. 220–242.

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