Small knowledge of thunderstorm weather safety
Knowledge of thunderstorm weather 1. What are the common sense of thunderstorm weather safety?
1. Don't make a phone call or answer a phone call during a thunderstorm and lightning, but turn off your mobile phone, because the electromagnetic waves of telephone lines and mobile phones will lead to lightning injuries.
2. Don't turn on the TV, computer, VCD player, etc. Unplug all power plugs during thunderstorms and lightning to avoid personal injury and electrical damage. 3, don't stand under the light bulb, don't take a shower.
4. Try not to go out. If you have to go out, you'd better wear rubber shoes and a raincoat, which can keep out lightning. 5. Try not to open the door or open the window to prevent lightning from hitting the room directly.
6. Don't stick your head and hands out of the window when you encounter lightning in the car. 7. Stay away from trees during a thunderstorm. Try not to run in big strides. You can choose buildings to shelter from the rain, but don't choose cars to shelter from the rain.
8. Don't connect the wires for drying clothes and bedding to the doors and windows. 9. Don't wear wet clothes, hats, shoes, etc. Walking in a thunderstorm.
For sudden lightning, the height should be lowered immediately, and the feet should be close together to reduce the harm caused by the step voltage. 10, when lightning strikes, don't get close to all power facilities, such as high-voltage line transformers.
2. What are the common sense of thunderstorm weather safety?
1, it is essential to close the doors and windows during a thunderstorm. At the same time, it is necessary to unplug all the power in the house in time, and it is best not to play with mobile phones and computers. Of course, never watch TV, or you will get hurt if the TV breaks down.
2. Even if the power supply is unplugged, the concentrated wires are still charged. It's best not to get too close to the wires, and try to stand under the light bulb. Because if the thunder is particularly serious, the light bulb may break, and standing under the light bulb is particularly dangerous.
3, can't take a shower, because the hot water appliance is charged. At this time, bathing may conduct electricity, which is likely to threaten life safety. It is best to unplug the water heater, and it is best not to turn on the water heater in thunderstorm weather.
4. Keep away from windows, walls, etc. And it is best not to stand barefoot on the ground. One thing to note here is that it is best not to use iron wire as a clothesline to connect the windows, which is easy to introduce lightning.
In case there is a thunderstorm outside, never hide under the big tree. This is the minimum awareness of lightning protection. In addition, you can't stay in high-rise platforms, separate huts, sentry boxes, etc. However, if there is really no place to hide, just squat down with your legs together three meters away from the tree.
Extended data:
The average current of lightning is 30,000 amps, and the maximum current can reach 300,000 amps. The voltage of lightning is very high, about 1 billion to 1 billion volts. The power of medium-intensity thunderstorm can reach10 million watts, which is equivalent to the output power of a small nuclear power plant.
In the process of discharge, due to the sudden increase of temperature in the lightning channel, the air volume expands rapidly, resulting in shock waves and strong lightning. When the charged Lei Yun is close to the protrusions on the ground, a violent discharge will occur between them. There will be strong flash and explosion roar at the scene of lightning discharge. This is the lightning and thunder that people see and hear.
Sogou encyclopedia-lightning
3. Pupils' knowledge of thunderstorm prevention
With the arrival of summer, there are more and more thunderstorms. In order to strengthen the safety management of schools in summer, let primary school students fully understand the harm of lightning and learn the knowledge of lightning protection, I will tell you some knowledge about lightning.
"When encountering thunderstorm weather, teachers and students outdoors should immediately enter the building and close the doors and windows. Don't take shelter from the rain under the big tree, don't use metal umbrellas, and try not to ride bicycles; Stay away from balconies, metal railings, metal security nets, wires and other conductors and external walls of buildings, do not use faucets and showers, try not to use telephones, and turn off electrical equipment such as televisions, computers and stereos. If there is no place to hide in the open field when there is lightning, you should try to find a low and concave place (such as a pit) to hide, or immediately squat down, put your feet together, put your arms around your knees, try to bow your head, and don't stand on the playground when it thunders.
4. Thunderstorm knowledge
In summer, there are often strong winds and thunderstorms. The wind came, flying sand and stones, overturning roofs and blowing down walls. During the storm, the dining tables and chairs in the street danced with the wind and hit pedestrians from time to time. Trees uprooted by strong winds, some injured pedestrians, some damaged cars, and some damaged courtyard walls ... all these were caused by strong convective thunderstorm clouds. So, how is the thunderstorm cloud formed?
In summer, direct sunlight makes the water on the ground evaporate faster than in winter, spring and autumn. The air close to the ground can receive more water vapor because of its high temperature, which leads to the decrease of air density, the lightening of air and the rising of the lightened air. With the increase of altitude, the temperature will gradually drop (0.6 degrees per 100 meters), and the air will gradually cool down. When the air is cool, it can't hold the original abundant water vapor. Some water vapor will condense into small water droplets, and the sky will be cloudy. So, why don't these little drops fall down quickly and turn into rain? This is because the water droplets are too small, and the rising hot air lifts them up and pushes the suspended water droplets higher and higher. Clouds are getting bigger and higher. This kind of cloud is called cumulonimbus cloud in meteorology, and its bottom is about 1000 meters above the ground.
When the small water droplets in the cumulonimbus cloud constantly collide and merge into larger water droplets, they begin to fall, while the hot air rising from the ground keeps rushing upwards, and the friction between them is charged. The rising airflow is positively charged and the falling water droplets are negatively charged. Over time, a large number of positive charges have accumulated at the top of cumulonimbus clouds, while many negative charges have accumulated at the bottom. Due to the negative charge at the bottom of cumulonimbus clouds, the ground is also positively charged.
The water droplets in the cloud merge and increase until the rising hot air can't hold it, and then fall straight from the cloud. The hot air at the lower level was drenched by rain and suddenly became cold. Instead of rushing up, it turned to the ground. At this point, the charge in the air began to discharge, accompanied by thunderous thunder. Because lightning travels at a speed of 300,000 km/s and thunder travels at a speed of 33 1 m/s, people first see lightning and then hear thunder. Sometimes the thunder drags on for a long time, which is caused by the thunder reflected back and forth from clouds, peaks and ground.
In China, thunderstorms mostly occur in hot, humid and bad weather from May to August.
5. Primary school students' knowledge of lightning protection and rain protection
With the arrival of summer, there are more and more thunderstorms. In order to strengthen the safety management of schools in summer, let primary school students fully understand the harm of lightning and learn the knowledge of lightning protection, I will tell you some knowledge about lightning.
"When encountering thunderstorm weather, teachers and students outdoors should immediately enter the building and close the doors and windows. Don't take shelter from the rain under the big tree, don't use metal umbrellas, and try not to ride bicycles; Stay away from balconies, metal railings, metal security nets, wires and other conductors and external walls of buildings, do not use faucets and showers, try not to use telephones, and turn off electrical equipment such as televisions, computers and stereos. If there is no place to hide in the open field when there is lightning, you should try to find a low and concave place (such as a pit) to hide, or immediately squat down, put your feet together, put your arms around your knees, try to bow your head, and don't stand on the playground when it thunders.
6. What are the safety knowledge of thunderstorm weather?
1. Don't stay on the high-rise platform in thunderstorm weather, and don't enter isolated shacks, sentry boxes, etc. In the open air.
2. Stay away from the exposed water pipes, gas pipes and other metal objects and power equipment in the building. 3. It is not advisable to hide under the big tree during a thunderstorm. If necessary, you must keep a distance of 3 meters from your torso, squat down and put your legs together.
4. If there are ants crawling on your head, neck and hands when thunder and lightning strike, and your hair stands on end, it means that lightning is coming. Get down on the ground quickly to reduce the risk of being struck by lightning, and take away the metal ornaments, hairpins and necklaces you wear. 5. If it is too late to leave tall objects due to outdoor thunderstorm, you should immediately find some dry insulation and put your feet on it. Never put your feet on the ground outside insulation, because water can conduct electricity.
6. When avoiding thunderstorm outdoors, be careful not to hold the ground with your hands. At the same time, put your hands on your knees, keep your chest close to your knees, and try to keep your head down, because your head is more vulnerable to lightning than other parts of your body. 7. When you hear thunder within a few seconds of seeing lightning outdoors, it means that you are in a dangerous environment near a thunderstorm. At this time, you should stop walking, put your feet together and squat down immediately. Don't get involved with people. It is best to use plastic rain gear and raincoat.
8. In thunderstorm weather, it is not advisable to open an umbrella or hold high badminton rackets, golf clubs and hoes in the wild. Not suitable for outdoor ball games. It is very dangerous to play golf and football in thunderstorm weather. It is not advisable to stay on the water surface or water edge; It is not advisable to wash clothes, fish, swim or play by the river. 9. In thunderstorm weather, it is not advisable to drive a motorcycle, ride a bicycle or run fast in the rain, because the greater the stride of the body, the greater the voltage, and the easier it is to hurt people.
10. If you see a high-voltage line that is broken by lightning outdoors, you should be vigilant at this time, because there is a step voltage near the breakpoint of the high-voltage line. People nearby must not run at this time, but should jump off the scene with their feet together.
7. Lightning tips
Lightning 1. What is natural lightning? Lightning is a spectacular and somewhat frightening discharge phenomenon accompanied by lightning and thunder.
Lightning is usually produced in cumulonimbus clouds with strong convection, so it is often accompanied by strong gusts and heavy rains, and sometimes accompanied by hail and tornadoes. The top of cumulonimbus clouds is generally very high, up to 20 kilometers, and there are often ice crystals on the top of the clouds.
The attachment of ice crystals, the breaking of water droplets and air convection make clouds generate charges. The distribution of charge in the cloud is complicated, but generally speaking, the upper part of the cloud is dominated by positive charges and the lower part is dominated by negative charges.
Therefore, a potential difference is formed between the upper and lower parts of the cloud. When the potential difference reaches a certain level, discharge will occur, which is our common lightning phenomenon.
The average current of lightning is 30,000 amps, and the maximum current can reach 300,000 amps. The voltage of lightning is very high, about 1 billion to 1 billion volts.
The power of medium-intensity thunderstorm can reach10 million watts, which is equivalent to the output power of a small nuclear power plant. In the process of discharge, due to the sudden increase of temperature during flashover, the air volume expands rapidly, resulting in shock waves and strong lightning.
When the charged Lei Yun is close to the protrusions on the ground, a violent discharge will occur between them. There will be strong flash and explosion roar at the scene of lightning discharge.
This is the lightning and thunder that people see and hear. What is lightning? Storm clouds usually produce charges, with negative charges at the bottom and positive charges at the top. They also produce positive charges on the ground, which move around with the clouds.
Positive and negative charges attract each other, but air is not a good conductor. Positive electricity rushes to treetops, hilltops, tall buildings and even above the human body, trying to meet negative clouds; Dendritic tentacles with negative charges extend downward and get closer to the ground.
Finally, the positive and negative charges finally overcome the air barrier and connect. A huge current rushed from the ground to the clouds along the conductive path, producing a bright flash.
The length of lightning may be only a few hundred kilometers, but it may also be several kilometers long. The temperature of lightning varies from 17000 degrees Celsius to 28000 degrees Celsius, which is 3~5 times the surface temperature of the sun.
The extreme heat of lightning caused the air along the way to expand violently. Air moves very fast, so waves are formed and sounds are made.
When lightning approaches, you hear a sharp crack; If it's far away, you hear rumbling. You can start the stopwatch after you see the lightning, press the stopwatch to stop when you hear the thunder, and then divide the number of seconds by 3 to get a rough idea of how many kilometers the lightning is from you.
Types of lightning ordinary lightning with twists and turns is called dendritic lightning. If the passage of dendritic lightning is blown to both sides by the wind, so that it seems that there are several parallel lightning, it is called strip lightning.
If two lightning branches seem to reach the ground at the same time, they are called bifurcated lightning. When lightning flashes between the negative and positive charges in the cloud, making the sky in the whole area bright, it is called sheet lightning.
Lightning that does not reach the ground, that is, lightning within the same cloud or between two clouds, is called cloud-to-cloud lightning. Sometimes this lightning will travel a long distance and land on the ground many kilometers away from the storm. This is called a "bolt from the blue".
The electric action of lightning sometimes forms a halo-like red light around tall and sharp objects. Usually in stormy seas, red light can be seen around the mast of a ship, so people borrow the name of the patron saint of sailors and call this lightning "the fire of St. elmo".
Super lightning refers to those rare lightning whose power exceeds ordinary lightning 100 times. The electricity generated by ordinary lightning is about 1 megawatt, while the electricity generated by super lightning is at least 1 megawatt, and may even reach trillions to 1 megawatt.
Clock Island in Newfoundland was obviously struck by a super lightning at 1978. Even the houses at 13 km away rattled, and the windows and doors of the whole village were sprayed with blue flames. When you read this article, there are about 1800 lightning strikes in the world.
They emit about 600 lightning flashes per second, of which 100 hits the earth. Lightning can transform some nitrogen in the air into nitrogen compounds, which can be washed to the ground by rain.
In a year, every hectare of land on the earth can get a few kilograms of this free fertilizer from the sky. Kampala, the capital of Uganda, and Java, Indonesia are the most vulnerable places to lightning strikes.
According to statistics, there are 300 days of lightning in Java a year. The most violent lightning in history was that 1975 hit a small house near Umtali in rural Zimbabwe, when 2 1 person died.
More than two thirds of lightning victims were attacked outdoors. Two thirds of the people survived.
Among the people killed by lightning, 85% are men, and most of them are between 10 and 35 years old. Most of the dead hid from lightning and rain under trees.
Sullivan may be the champion who was struck by lightning. He is a retired forest manager who was struck by lightning seven times.
Lightning once scorched his eyebrows, his hair, his shoulders, ripped off his shoes and even threw him out of the car. He said simply, "Lightning will always find me."
The harm of lightning to human body includes the direct action of current, overpressure or electric power and high temperature. When a person is struck by lightning, the current will pass through the human body quickly. In severe cases, it will lead to heartbeat, respiratory arrest and brain tissue hypoxia and death.
In addition, when lightning strikes, sparks will be generated, which will also cause different degrees of skin burns. Lightning injury can also cause dendritic lightning stripes, epidermal peeling, intradermal bleeding, eardrum or visceral rupture.
Precautions for lightning protection: Lightning current generated during lightning stroke is the main source of harm, and its harm includes direct lightning, induced lightning and intrusive lightning guided by overhead lines. For example, overhead lines used in various lighting, telecommunications and other facilities may introduce lightning into the room, so strict preventive measures should be taken.
First, lightning prone parts 1. High-rise buildings, storage tanks, etc. lacking lightning protection devices or unqualified lightning protection devices. ; 2. The metal roof is not well grounded; 3. Buildings and trees in wet or open areas; 4. Due to the conductivity of flue gas, chimneys are particularly vulnerable to lightning strikes; There is a radio in the building, but there is no lightning arrester and no good grounding. Second, lightning protection method 1.
8. The second-grade students' understanding of thunderstorms in China.
I hope you can accept that in summer, direct sunlight makes the water on the ground evaporate faster than in winter, spring and autumn.
The air close to the ground can receive more water vapor because of its high temperature, which leads to the decrease of air density, the lightening of air and the rising of the lightened air. With the increase of altitude, the temperature will gradually drop (0.6 degrees per 100 meters), and the air will gradually cool down.
When the air is cool, it can't hold the original abundant water vapor. Some water vapor will condense into small water droplets, and the sky will be cloudy. So, why don't these little drops fall down quickly and turn into rain? Because the water droplets are too small, the rising hot air lifts them and pushes the suspended water droplets higher and higher.
Clouds are getting bigger and higher. This kind of cloud is called cumulonimbus cloud in meteorology, and its bottom is about 1000 meters above the ground. When the small water droplets in the cumulonimbus cloud constantly collide and merge into larger water droplets, they begin to fall, while the hot air rising from the ground keeps rushing upwards, and the friction between them is charged.
The rising airflow is positively charged and the falling water droplets are negatively charged. Over time, a large number of positive charges have accumulated at the top of cumulonimbus clouds, while many negative charges have accumulated at the bottom.
Due to the negative charge at the bottom of cumulonimbus clouds, the ground is also positively charged. The water droplets in the cloud merge and increase until the rising hot air can't hold it, and then fall straight from the cloud.
The hot air at the lower level was drenched by rain and suddenly became cold. Instead of rushing up, it turned to the ground. At this point, the charge in the air began to discharge, accompanied by thunderous thunder.
Because lightning travels at a speed of 300,000 km/s and thunder travels at a speed of 33 1 m/s, people first see lightning and then hear thunder. Sometimes the thunder drags on for a long time, which is caused by the thunder reflected back and forth from clouds, peaks and ground.
In China, thunderstorms mostly occur in hot, humid and bad weather from May to August. [1] It mainly occurs in the south of the Yangtze River in spring and autumn, with the least in winter. After 10, the probability of thunderstorm weather in the vast area north of the Yangtze River is small.