The key points of physical safety electricity use in junior high school ~ ~ need to be explained in detail ~ ~

The topic of safe use of electricity and protection teaching

teaching

Target 1, knowledge target: ① Understand the cause of electric shock and know the safe voltage value to human body.

(2) Master the necessary common sense of safe use of electricity and common protective measures for safe use of electricity.

2. Ability goal: Through the teaching of this course, let students learn to use electricity safely and have the ability to protect themselves.

3. Emotional goal: to enable students to establish a sense of safe use of electricity, enhance their sense of safety responsibility, understand the value of physical science, and cultivate a rigorous scientific attitude.

Common sense of key safe electricity use

Common sense of difficult and safe use of electricity

Teaching methods of explanation, exploration and discussion

Multimedia teaching AIDS, videos, long straight wires (2 different colors)

Mainly to teach students activities.

The introduction of new class electricity is an indispensable power source in modern society, and civilized life cannot be separated from electricity. But on the other hand, the use of electricity also has its two sides. If used properly, electric energy will bring us great benefits, and if used improperly, it will cause great harm. Therefore, it is very important for us to master the basic knowledge of safe use of electricity.

Understand the importance and harm of electricity to human beings.

1, design of two teaching processes: electric shock and safe use of electricity

Multimedia playing video

(1), accident case of illegal electricity use.

Case 1: At noon on March 30th, 20 10, a fire broke out in No.4 Hao Han Road, Wenjiang District, "the automobile parts distribution center in Chang 'an District, Wan You, Chengdu". Thousands of square meters of warehouses collapsed and the stocks were completely burned, which triggered the worst fire in Chengdu in recent years. After investigation, the cause of the fire was that the workers had obvious illegal behaviors during the welding operation: they did not take safety protection measures and did not conduct safety review on the site after the construction.

Case 2 On the afternoon of April 23, 2004, at the project site of Huizhou University Apartment Building 12, when the welder Xu went to the third floor to weld the column rebar, the welder lacked safety protection and the special protection zero line was not in place. Xu did not use the electric shock protector, welder's gloves, insulating shoes, etc. And was immediately electrocuted.

Case 3: Ten students from a medical college practice in a hospital in Jinan. 12 am on October 22nd,1998,65438+They accidentally caught fire with an electric stove, resulting in 5 deaths and 5 burns.

Case 4: On February 8, 2009, a fire broke out in Suwu Shepherd Hotel in Harbin. After investigation, it was preliminarily determined that the fire was caused by the overload of electricity in the distribution box in the cable shaft on the second floor of Muyang Hotel in Su Wu, and the fire spread rapidly along the cable shaft. The door of the cable shaft on the thirteenth floor was not properly closed, and smoke came out from the thirteenth floor, causing a resident to choke to death by smoke during his escape.

Case 5: On 2001March1March 12, a disaster occurred in the dormitory of the third section of Guan Jing Road in Dujiangyan City due to improper installation and use of air conditioners, resulting in direct property losses of more than 200,000 yuan. 65438+At 20: 20 on February 23rd, at No.9-27 Qianjin Street, Hesheng Town, Wenjiang County (Hesheng Department Store Head Office), the flammable bamboo ceiling caused a disaster due to the short circuit of the lighting circuit of the warehouse ceiling on the west side of the store 19-2 1. Due to the timely rescue, no casualties were caused, and the direct property loss reached more than 260,000 yuan.

(2) Discuss and ask questions.

What enlightenment did the case that happened around you bring to us? What was the cause of the accident? Under what circumstances can electric shock cause death? Emergency measures after electric shock? What are the consequences of illegal use of electricity? How to use electricity safely?

(3) The human body resistance is often taken as 1500 ohm-2,000 ohm, and the value is different in different humidity environments. The higher the humidity, the smaller the human body resistance (for example, the minimum resistance is only 500 ohms when water enters), and the corresponding safe voltage is also different (the human body safe voltage is generally not higher than 36V).

2, low voltage electric shock and high voltage electric shock

(1) Low voltage electric shock

The household circuit voltage is 220V, and the industrial and agricultural electricity voltage is 380V, both of which belong to low-voltage lines. The causes of low-voltage electric shock accidents are: single-phase electric shock and two-phase electric shock. Causes and consequences of electric shock: direct contact between human body and power supply generates electricity, and a certain amount of current passes through human body, resulting in tissue damage, dysfunction and even death. The longer the electric shock time, the more serious the damage to the body. Low voltage current can stop the heartbeat (or ventricular fibrillation, followed by respiratory arrest). Due to the strong stimulation to the central nervous system, the high-voltage current first stops breathing, and then the heartbeat stops.

(2) Multimedia pictures of high voltage electric shock demonstrate arc electric shock and step voltage electric shock.

High voltage (above 1000V) electric shock mainly includes arc electric shock and step voltage electric shock.

3. Moral education: use electricity safely in family, school, dormitory and laboratory.

(1) dormitory electricity safety

(1) It is strictly forbidden to change the electrical facilities in the dormitory area without permission. If any damage is found to the electrical facilities in the dormitory area, report it in time for timely maintenance.

② Do not connect plugs or wires privately in the dormitory, do not use electrical appliances other than those provided by the school, do not use troubleshooting, and do not use high-power electrical appliances such as electric stoves, heaters and quick heating in the dormitory.

(3) The power supply should be disconnected when the water dispenser is not burning hot water.

(4) Save electricity, so that people can turn off the power supply.

(2) classroom electricity safety

① The power sockets used in the classroom must be qualified products, and should be replaced in time if damaged.

(2) Don't wipe the live equipment with a wet cloth, and don't sprinkle water on the live equipment or wires.

(3) The mobile phone cannot be charged overnight, and the classroom electrical equipment should be turned off in time when no one is there.

(3) Laboratory electricity safety

① When using electricity in the electronic laboratory, you must abide by the rules and regulations of the laboratory.

(2) all exposed parts of the power supply should be equipped with insulation devices, and the metal shell of all electrical appliances should be connected to the grounding wire.

③ When disassembling the experimental equipment, cut off the power supply first.

4. Common sense of safe electricity use

(1), read the instructions carefully before using electrical equipment and master the correct operation method.

(2) Don't buy fake and inferior electrical appliances, wires, trunking (pipes), switches, plugs and sockets.

(3) Under normal circumstances, electrical equipment should be cut off immediately after use.

(4) It is best to use your right hand when operating the power supply and switch.

(5) When electrical equipment is found to smoke or smell, the power supply should be quickly cut off for inspection; Found damaged wires should be replaced in time or wrapped with insulating tape, and ordinary medical tape is prohibited.

(6) It is best to use a single socket for each electrical equipment. Don't use a multi-purpose socket for multiple electrical appliances, so as not to affect each other and cause some unexpected injuries.

(7) Do not touch switches, sockets, plugs and various electrical power interfaces with wet hands or bare feet. Do not wipe lighting fixtures and electrical equipment with a wet cloth.

(8) If a ground wire or a wire immersed in water is found outdoors, whether it is charged or not, it shall be regarded as charged. Stay away from it, don't pick it up by hand, and notify the power supply department immediately.

(9) In the event of an electrical fire, the power supply must be cut off before extinguishing the fire, and it cannot be cut off temporarily. You can use carbon dioxide and carbon tetrachloride (12 1 1) fire extinguishers and dry powder fire extinguishers to extinguish the fire, but you must never spray with water and foam extinguisher.

5, electric shock emergency measures

(1), if someone gets an electric shock, turn off the switch and cut off the power immediately. If you can't disconnect the power supply in time, you can use dry sticks, belts, rubber products and other insulating items to contact the charged items on the electricians.

(2) Immediately call the police and give first aid.

(3), untie the tight clothes that hinder the breathing of the person who gets an electric shock, check the mouth of the person who gets an electric shock, and clean up the oral mucus. If there are false teeth, they should be removed.

(4), immediately on-site rescue. If breathing stops, artificial respiration should be used for rescue; If the heart stops beating, artificial chest compressions should be performed for rescue.

(5) If there is an electric burn wound, you should go to the hospital in time after dressing it.

Overview of safe electricity use

Lamp holder wires and switches, if damaged, should be replaced quickly; Hang clothes away from wires, pay attention to prevent electric shock and ensure safety; Install leakage protector to effectively prevent accidents; Do not splash water with electricity when electrical appliances smoke or catch fire; Power failure and fire fighting must abide by the rules, and don't panic when cutting off the power supply first; If someone gets an electric shock, call the police to cut off the power supply; If it is difficult to pull the switch, dry the wooden stick and connect the wire; People who get an electric shock should stay away from the power supply immediately, and don't neglect the rescue; Artificial respiration and compression, cardiotonic injection can not be used; Use electricity safely every day, and electricity accidents can be prevented; * * * With everyone's concern, campus electricity will be safe. Pay attention to safety before class and add a string to your mind; Pay attention to classroom safety and ensure safe operation; Pay attention to safety after work, and the alarm will ring.

Watch multimedia videos to understand the fire and loss caused by careless use of electricity, and understand the importance of electricity safety.

Discuss the harm of electricity consumption and the matters needing attention in daily safe electricity consumption.

Understand the human body's resistance in different environments.

Learn the knowledge of low-voltage electric shock and master two situations of low-voltage electric shock. Demonstrate two kinds of low-voltage electric shocks with long straight wire teaching AIDS.

Moral education: the harm of low-voltage electric shock to human body

Learn two ways of high voltage electric shock.

Moral education infiltration emphasizes that under the lightning tree, electric shock may occur around the place where the lightning rod leads out, and it will rain when it thunders, so we should pay attention to avoiding these places for safety.

Understand the knowledge of safe use of electricity in schools.

Thinking and homework 1, class discussion 2, exercises after class

Safe use of electricity and blackboard protection

1, electric shock and safe use of electricity

The key to the harm caused by current to human body: first, the magnitude of current, and second, the length of electrifying time.

Anti-electric shock: Do not touch the low-voltage charged body, and do not approach the high-voltage charged body.

2. Safety of electricity consumption in daily life

Fifth, teaching reflection.