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How many kilometers from lightning to thunder. Thunder, lightning. distance between them. Data. The principle of "behavior" of lightning

Instruction

Lightning is dangerous to human life. However, ironically, it is through the fault of people that there are more and more of them. This happens due to an extremely irresponsible attitude to the environment: ambient air pollution in megacities increases the heating of the air and the rise of steam condensate into the atmosphere. This amplifies the electrical intensity in the clouds and provokes lightning discharges.

The need to determine the distance to lightning is caused not only by the need to expand one's horizons, but also by the elementary instinct of self-preservation. If it is too close, and you are in an open space, then it is better to run away from there as quickly as possible. The electric current chooses the shortest path to the ground, and skin covering- an excellent conductor for him.

Start counting seconds as soon as you see a flash of light in the sky, use a clock or a stopwatch. As soon as the first roll of thunder is heard, stop counting, so you will get time.

To find the distance, you need to multiply the time by the speed. If accuracy is not very important for you, then it can be taken equal to 0.33 km / s, i.e. multiply the number of seconds by 1/3. For example, according to your calculations, the time to lightning was 12 seconds, after dividing by 3 you get 4 km.

To determine the distance to lightning more accurately, take the average speed in the air as 0.344 km/s. Its true value depends on many factors: humidity, temperature, type of terrain (open space, forest, urban high-rise buildings, water surface), wind speed, etc. For example, in rainy autumn weather, the speed of sound is approximately 0.338 km / s, in dry summer heat - about 0.35 km / s.

Dense forest and tall buildings significantly slow down the speed of sound. It decreases due to the need to go around numerous obstacles, diffraction. It is quite difficult to make an accurate calculation in this case, and most importantly, it is not advisable: despite the fact that lightning will not strike the ground, it can hit a tall tree next to you. So wait it out between low-growing trees with a dense crown, best of all on your haunches, and if you are on a city street, then take cover in a neighboring building.

Notice the wind. If it is strong enough and blows in your direction away from the lightning, then the sound is coming faster. Then its average speed can be taken approximately equal to 0.36 km/h. When the direction of the wind is from you to the lightning, the movement of sound, on the contrary, slows down and the speed is approximately equal to 0.325 km/h.

The average length of lightning reaches 2.5 km, and the discharge extends over a distance of up to 20 km. Therefore, you should leave the open place as soon as possible in the nearest building or structure. Remember that when lightning approaches, you need to close all windows and doors and turn off electrical appliances, as damage can occur through the antenna and through the network and harm your equipment.

Lightnings are not only terrestrial, but also intra-cloud. They are not dangerous to those on the ground, but they can damage flying objects: airplanes, helicopters and other vehicles. In addition, a metal object that has fallen into a cloud with a strong electric field that can support, but not create a charge, can initiate lightning and provoke its appearance.

Instruction

So, expect lightning with a stopwatch in hand. At the time of the flash, start the stopwatch, when you hear thunder, turn off the stopwatch. As a result, you will get the thunder delay time - that is, the time it took for the air vibration to travel from the place of the discharge to you.

Further, the distance, according to the well-known formula, is the product of the speed of movement and time. You have time. As for speed, for rough calculations it is enough to remember the value of 343 meters per second. If you want to calculate the distance more or less accurately, then you should remember that sound travels faster in a wet place than in a dry one, and faster in a hotter place than in a cold one. For example, in a cold rainstorm, the speed of sound will be 338 m/s, and in a hot and dry summer it will be 350 m/s.

Now consider. For example, it took 8 seconds from the flash of lightning to the sound of thunder.
Take the speed of sound - 343 m/s, then the distance to the lightning will be 8 * 343 = 2744 meters, or (rounded up) 2.7 kilometers. If the air temperature is 15 moderate rain), then the speed of sound will be 341.2 m / s, and the distance will be 2729.6 m (can be rounded up to 2.73 km).

You can enter a tolerance for wind direction. If the wind blows in the direction from the lightning to you, the sound will travel this distance somewhat faster, and if the wind blows away from you towards the lightning, it will travel this distance somewhat more slowly. For rough calculations, it is enough to remember that in the first case (wind to lightning) the distance must be reduced by 5%, and in the second case (wind from lightning) increased by 5%. Thus, with a thunder delay of 8 seconds and a speed of sound of 343 m / s, with the wind direction from lightning to you, the distance of 2744 meters must be increased by 137.2 m.

Sources:

Table of the dependence of the speed of sound on temperature and humidity
sound distances

Lightning usually occurs as a bright zigzag flash in thunderclouds and is accompanied by thunder. Its electrical discharge reaches 100,000 amperes, and its voltage reaches several hundred million volts. To determine the distance to lightning, you need to calculate the time in seconds from the flash to the first peals of thunder.

You will need

- stopwatch or watch$
- calculator.

Instruction

Start counting seconds as soon as you see a flash of light in the sky, use a clock or a stopwatch. As soon as the first roll of thunder is heard, stop counting, so you will get time.

If by all indications it is clear that thunderstorms cannot be avoided, we act depending on the situation.

Rules of conduct during a thunderstorm:

Option 1. You are at home

if a thunderstorm caught you at home, close windows and vents, move away from the window, avoid drafts that could attract fireballs,
do not touch water taps and batteries,
don't use a regular phone- even here you can be overtaken by an electric discharge,
try to stay away from electrical outlets;
disconnect from electricity computer, TV and other electrical appliances;
don't talk on your cell phone;
it is better not to heat the stove or fireplace at this time, since the smoke coming out of the chimney has a high electrical conductivity, and the likelihood of a lightning strike into the chimney increases.

Option 2. You are in the city

Do your best in the city rather take cover in a shop or apartment building. They have reliable lightning protection, unlike public transport stops. If there are no such options, wait out a thunderstorm by squatting under low plantings.

Mobile phone while on the street immediately disable.

Using a mobile phone outdoors during a thunderstorm poses a serious threat to life and health due to the danger of lightning. There have been numerous cases of people dying from lightning strikes while talking on a mobile phone.

Option 3. You are in the forest

Lightning in a forest almost never strikes the ground, with the exception of clearings, because trees are natural lightning rods, and the probability of lightning hitting a particular tree is directly proportional to its height.

Stay away from tall trees . The smartest option sit between low trees with dense crowns. At the same time, determine the approximate height of the trees you have chosen and try be placed from them at a distance not exceeding this height. Let's say the height of the trees is about 4-5 meters, respectively, it is necessary to place between them so that each of the trees is at least 4-5 meters away. This is called the "cone of protection".

Moreover, it must be remembered that most often lightning strikes oak trees, poplars, elms - as they contain a lot of starch. Less often - in spruce, pine, fir - as they contain a lot of oils, therefore they have great electrical resistance and are less likely to be struck by lightning. Quite rarely - in birches, maples.

Sit better in the so-called fetal position"- the back is bent, the head is lowered on the legs and forearms bent at the knees, the feet are joined together.

When choosing a shelter for yourself, pay attention to whether there are nearby trees that were previously hit by a thunderstorm, split. In this case, it is better to stay away from this place. The abundance of trees struck by lightning indicates that the soil in this area has a high electrical conductivity, and a lightning strike in this area is very likely.

It is also best to pitch tents in a small clearing in the middle forest. Putting up tents in the open is dangerous.

Option 4. You are in the field

At the first sign of an approaching thunderstorm: move to the side reliable nearest shelters(forest, village), moving away at the same time from separate trees or groves. With the onset of a thunderstorm, if you still haven't made it to shelter: sit as close to the ground as possible. It should be remembered that sandy and stone soils are safer than clay soils.

It is forbidden: move quickly, hide in haystacks, under lonely standing trees or islands of trees, especially touch them with hands and other parts of the body. The psychology is such that a person tends to see protection in something big and powerful. In a thunderstorm, the reverse law works: the smaller you are, the more chances you have not to fall under the category. Therefore, we go around the trees.

Option 5. You are in the river, and there is a water meadow nearby

It is forbidden: climb into the water; hide in the floodplain bushes and, again, under the trees. It is necessary as soon as possible (but not running, if the thunderstorm has already begun) to get to the nearest forest (but not individual trees in the open area) or to the village. At the same time, try to avoid, two hundred meters away, lonely trees and other tall objects.

A person on a boat, when a thunderstorm approaches, should immediately land on the shore.

Option 6. The storm caught you in the car

Many people mistakenly believe that it is dangerous to wait out a thunderstorm while sitting in a car. In fact, the machine protects the people inside quite well, since even with a lightning strike, the discharge goes through the surface of the metal. Therefore, if a thunderstorm caught you in the car, close all windows and wait until the bad weather passes.

However not should touch before door handles and other metal parts. including up to cell phones. Spare your eardrums - in a thunderstorm, you can get a sonic boom through a mobile phone in your hands.

Option 7. You are on a bike

A bicycle and a scooter, unlike a car, will not save you from a thunderstorm.

If you are caught in a thunderstorm while riding a bicycle or motorcycle, stop moving, leave them and wait out the storm at a distance about 30 meters away.

Option 8. If you are on a hike

During a thunderstorm, all metal objects: axes, saws, shovels, knives, dishes, etc. - must be folded 15-30 m from the camp or people.

From the soil, especially if it is wet, it is necessary to isolate, placing a heat-insulating rug, air mattress, branches, spruce branches, in extreme cases, stones, ropes, clothes, shoes, etc. under you. at the same time, it is necessary to strive so that the insulator is as dry as possible!

You should sit in a group, bending your back, lowering your head on your legs and forearms bent at the knees, connect your feet together. The body should have the least contact with the ground. It is desirable to remove wet clothes and put on dry ones, in extreme cases, carefully squeeze them out. Wet body and clothing increase the risk of being struck by lightning.

When the storm starts, put out the fire. Smoke is a good conductor of electricity. There were, for example, cases when lightning struck a low pipe, although there was a tall one nearby. And all because the "shorty" smoked with might and main.

When sheltering from a thunderstorm, also avoid characteristic faults on the ground. Experts call them "lightning nests" - they are the most conductive areas of the soil.

On the way, the group is better to disperse. Go one at a time, don't rush.

During a thunderstorm, in no case do not run and do not fuss.
You can not be in wet clothes and shoes.

Ball lightning

Approximately a year ago, on the morning of July 12, residents of the 5th lane Yamnitsky witnessed one of the mysterious phenomena of the nature of ball lightning. A large light ball with a diameter of about 2 meters came into contact with a television antenna installed on one of the houses, after which it exploded and, having split in two, disappeared, leaving behind three sources of ignition on the roof at once. At the time of the incident, there was a girl born in 1994 and her 48-year-old father in the house, who was doing housework in the courtyard of the house. Neighbors reported the fire. When rescuers arrived, the house was on fire. As a result of the fire, the roof was destroyed by fire, property in the house was damaged.

Ball lightning can suddenly appear anywhere, even indoors. There were cases of her appearance from a telephone receiver, an electric razor, an outlet. Eyewitnesses claim that ball lightning can enter a room through narrow cracks, pipes, and even a keyhole. The size of ball lightning can be from a few centimeters to several meters. Usually it easily floats or rolls above the ground, sometimes jumps. Ball lightning can appear and disappear without causing harm to a person or a room. And it can leave behind a hole in the door and the smell of ozone. She often explodes. Statistics says that in 80% of cases explosions were not dangerous, serious consequences occurred in 10% of explosions.

What to do if, nevertheless, ball lightning has flown into your house?

When meeting with ball lightning, keep calm and stop the slightest movement.

Shouldn't run away from ball lightning, because you can cause an air stream, through which a clot of energy will fly purposefully after you.

No need to approach her, touch her with anything, as an explosion may occur.

Important!!!

If there is a person next to you, struck or shell-shocked by lightning, do not be afraid to touch him- no charge remains in the victim's body. It must be remembered that not every lightning strike is fatal!

A person can be helped by providing first aid. The main cause of death in a lightning strike is a violation of the activity of the heart and lungs. Therefore, the victim should do artificial respiration and heart massage without stopping for more than a minute, and stop only when the victim has obvious signs of death.

If a thunderstorm takes you by surprise, you need to remember the following:

lightning never strikes a bush;
avoid isolated trees;
put metal objects aside;
do not stand under an open umbrella;
do not touch electrical objects and take them out of pockets;
if possible, wait out the storm in the car;
stay away from tall metal structures;
do not swim, do not ford the river, move away from the reservoir.

Once in extreme conditions, act decisively, using all the baggage of your knowledge and skills.

27/07/2010

Scientists have been studying lightning for hundreds of years. Although they know perfectly well what causes lightning, these mysterious flashes of electricity hold many more secrets.

At reading that the holiday season has begun in the summer, we suggest that you replenish your knowledge box with useful and interesting facts about lightning. Let's consider how true some myths about lightning are.

Myth: tornadoes and hurricanes are more dangerous than lightning.
Fact: lightning kills more people each year than tornadoes or hurricanes. More people die from floods than from lightning.

Myth: even at home you can be struck by lightning.
Fact: Perhaps the safest place during a thunderstorm is inside the house, but that doesn't mean you shouldn't take precautions.

If lightning strikes a building, electricity most likely will pass through the plumbing or wiring before going into the ground. Therefore, during lightning, do not talk on a wired telephone, stay away from running water (do not take a shower, do not wash dishes and hands). Do not use a cooker, computer or other appliances connected to the mains.

Myth: lightning always brings down planes.
Fact: in reality, lightning strikes planes regularly, but rarely causes them to crash. On average, every aircraft is struck by lightning at least once a year. Most aircraft are made from aluminum, which is a good conductor electricity, so there are strict safety regulations for aircraft.

Myth: During thunderstorms, turn off electronic devices.
Fact: current surge can damage electronics, even if lightning does not hit your home. If you are unsure of the operation of the surge protector, turn off your computer, TV, and other electronics. If you start turning off appliances during a thunderstorm, there is a chance of electric shock, so this should be done before the thunderstorm starts.

Myth: during a thunderstorm it is dangerous to be in the car.
Fact: in fact, cars are one of the safest places during a thunderstorm if you can't get into a building. Just make sure your car has a secure and strong roof: a golf cart or convertible won't work.

Myth: lightning does not strike twice in the same place.
Fact: during a thunderstorm, lightning can strike the same place several times.

Myth: It is not safe to be outside during a thunderstorm.
Fact: If you are outside during a thunderstorm, try to take shelter in a grounded building or in a car. If this is not possible, then the following tips will help minimize the risk: avoid open spaces and tall objects (such as trees) standing alone. Stay away from water - it conducts electricity well. Do not lie down on the ground - this will increase the contact area, because if lightning strikes the ground near you, then the smaller the contact area, the less current will flow into you.

Myth: It is necessary to stay at home for another half an hour after the end of the thunderstorm.
Fact: in most cases, lightning strikes people not in the midst of a thunderstorm. According to the US National Weather Service (NMS), lightning can strike from 15 km away from where it rains, so if you hear thunder, you are in a lightning threat zone.

The NMS advises to adhere to the following advice: “If you hear thunder, then wait at home. It will be safe to leave the house half an hour after the last thunder rumbled.

Myth: You can determine the distance to a thunderstorm by counting how many seconds passed from the flash of light to the thunder.
Fact: Surprisingly, this childish trick really works. Light travels faster than sound, so we first see a flash of light and then a roll of thunder.

To determine the distance to a thunderstorm, you need to know the speed of sound: it moves at a speed of 1 km in 3 seconds .

In the section on the question How can I measure the distance to a thunderstorm? given by the author Aggressive noob the best answer is the distance to a thunderstorm can be determined by the time between a flash of lightning and a roll of thunder (1s - distance 300-400 m, 2s - 600-800 m, 3s - 1000 m)

Answer from Ekaterina Kurzeneva[guru]
For some reason, my parents explained to me this way: Count the seconds between the flash of lightning and the first clap of thunder. 1s-1 km.

Answer from Vasisualy Levaterenolovich[guru]
It was found that the speed of sound is 171 toise per second, which corresponds to 337 m / s. Therefore, 3 sec ~ kilometer

Answer from Serrrega[guru]
No.. I'm not against physics.. .But.. I want to put in my twenty cents... .Maybe I'm wrong. . But a thunderstorm does not COMING from one point... .This is generally a global phenomenon... .And counting the seconds between the appearance of lightning and thunder is incorrect, you'll excuse me... .I observed thunderstorms when lightning was present in the form of a flash for three seconds within a radius of 180 degrees.. (left-right-front). And the thunder rumbled. then .... peal and stereo ... Your subwoofers and stereo effects are resting ... And how is it???? This is Moscow suburbs... I don't go far... I saw lightning but didn't hear thunder.. I heard thunder.. But I didn't see lightning.. How is that? How is it with D. Granin? "I'm going to the storm" 🙂

Answer from B and x r b[guru]
Hello!
Everything is pretty simple. Turn on the stopwatch at the moment of the lightning flash, and turn it off when the sonic boom begins. Multiply the number of seconds by 340 (cf. the speed in m/s of sound) and get the distance to the lightning in meters! If you make several such observations in a row and write down the results, you can calculate whether a thunderstorm is approaching you or moving away from you, and even at what speed it happens!
But at the same time, you need to keep in mind that lightning can have a length of several kilometers (see photo) and therefore the sound comes to you with a time shift from different parts of the lightning and therefore the thunder begins to "grumble" as the sound approaches from more distant sections of the lightning. At the same time, close lightning gives a higher-frequency sound, and distant lightning gives a low-frequency one, since at large distances the high frequencies of sound "extinguish", and long-wave low-frequency ones penetrate long distances, which is why only low-frequency "grunts" come from distant lightning.
I am enclosing a photo of the lightning, which, according to the calculations of its parameters, showed that the thickness of the lightning rod was about 50 m!
All the best.