"Drilling Wood to Make Fire" PPT download

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"Drilling Wood to Make Fire" PPT download

Part One: The legend of drilling wood to make fire

The earliest primitive people did not know how to use fire, so they ate everything raw. Not only eating raw plant fruits, but also the wild beasts they brought, they also devoured them alive, with hair and blood on them. Later, the use of fire was invented. The phenomenon of fire has long existed in nature. When volcanoes erupt, there is fire. When there is thunder and lightning, fire will also break out in the woods. But when primitive people began to see fire, they didn't know how to use it. Instead, they were scared to death. Later, I occasionally picked up a beast that had been burned to death and tasted it. It tasted delicious.

After many experiments, people gradually learned to use fire to burn things to eat, and they also found ways to preserve the fire so that it would last all year round. After a long period of time, people drilled hard and sharp wood into another hard wood to produce sparks; some also knocked flints to produce fire. This shows that workers can make fire. Who invented drilling wood to make fire?

Part 2: The principle of drilling wood to make fire

Drilling wood to make fire is based on the principle of friction and heat generation. During rapid friction, kinetic energy is converted to generate a large amount of heat energy. When the rate of heat energy generation is greater than the rate at which the object dissipates heat, the temperature will continue to rise. When the ignition point is reached, a fire is lit. .

Energy transformation in drilling wood to make fire

Mechanical energy (rotating stick)

Thermal energy (friction heat generation)

What other phenomena in life are the conversion of mechanical energy into thermal energy?

Part Three: Extended Research

The ancients used methods such as (drilling wood to make fire, Yangsui to make fire, lightning to make fire, fire sickle and flint to make fire) to obtain fire.

Fire is the earliest (natural force) utilized by human beings. The use of fire announced the end of human history (rubbing hair and drinking blood) and was a big step forward in the journey of human civilization.

According to historical records, as early as the Western Zhou Dynasty, that is, the 11th century BC, more than 3,000 years ago, our ancestors invented "making fire with Yang Sui". The so-called Yangsui is a metal concave mirror that can gather sunlight and ignite flammable materials such as moxa to obtain fire.

The fire sickle is a small piece of curved steel, and the flint is a piece of flint. The fire sickle strikes the flint, causing sparks to ignite the tinder.

Part 4: After-class exercises

1. The methods used by the ancients to make fire include (drilling wood to make fire, Yangsui to make fire, lightning to make fire, fire sickle and flint to make fire), etc.

2. When the Shenzhou-6 return capsule entered the atmosphere, it burned violently. This was because (the return capsule had severe friction with the atmosphere)

3. Fire is the earliest (natural force) utilized by human beings. The use of fire declares the end of human history (rubbing hair and drinking blood) and is a big step forward for human beings on the journey of civilization.

4. The principle of drilling wood to make fire is (friction heat generation)

Keywords: Qingdao version fifth grade science PPT courseware for the second volume free download, drilling wood to make fire PPT courseware, .PPT format;

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"Drilling Wood to Make Fire" PPT courseware download:

Download the PPT courseware of "Drilling Wood to Make Fire" Part One: Introduction of new lessons According to records, all kinds of food eaten by ancient people were raw. Therefore, people's life span is relatively short, usually around the age of twenty, and a special phenomenon occurs by chance. That..

"Drilling Wood to Make Fire" PPT courseware:

"Drilling Wood to Make Fire" PPT Courseware Part One: The Definition of Drilling Wood to Make Fire There is no fire in wood itself, so where does fire come from? The two pieces of wood rub against each other and generate heat. The generated heat has no time to diffuse into the air. It accumulates more and more, and the temperature gradually rises...

"Drilling Wood to Make Fire" PPT:

"Drilling Wood to Make Fire" PPT Part One Content: Drilling Wood to Make Fire Students, do you know how ancient people used fire? Do you know how people ate before they knew how to use fire? What is the significance of humans starting to use fire? Fire was the first thing humans used...

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Update Time: 2024-12-04

This template belongs to science courseware Qingdao Edition Fifth Grade Science Volume 2 industry PPT template

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