Lesson 25 of Volume 2 of Fourth Grade Chinese Language Two iron balls hit the ground at the same time?

Lesson 25 of the second volume of the fourth grade of Chinese language "Two iron balls hit the ground at the same time" uses specific examples to show the character's qualities. I have compiled the text materials of "Two Iron Balls Landed at the Same Time" for teachers and students of fourth grade. I hope everyone will learn something!

Lesson 25 of the second volume of Chinese Language for Grade 4 "Two Iron Balls Landed at the Same Time" Text

Galileo Galilei was a great Italian scientist in the 17th century. When he was in school, his classmates called him "the debater." The questions he asked were unusual and often difficult for teachers to answer.

At that time, people who studied science believed in Aristotle and regarded the words of this Greek philosopher more than 2,000 years ago as truth that cannot be changed. If anyone doubts Aristotle, people will blame him: "What do you mean? Do you want to violate the truth of mankind?"

Aristotle once said: "Two irons If a ball weighs 10 pounds and a ball weighs 1 pound, and it falls from a height at the same time, the 10-pound ball will hit the ground first, and its speed will be 10 times that of the 1-pound ball." This sentence caused Galileo to question. He thought: If this sentence is correct, then if these two iron balls are tied together, the slower falling iron ball will drag the faster falling iron ball, and the falling speed should be slower than the 10-pound iron ball; however, if the two iron balls are tied together, the slower falling iron ball will drag the faster falling iron ball. The two iron balls tied together weigh 11 pounds as a whole and should fall faster than the 10-pound iron ball. In this way, two opposite conclusions can be drawn from one fact. How to explain this?

Galileo repeatedly conducted many experiments with this question, and the results all proved that Aristotle’s The sentence was indeed wrong. Two iron balls of different weights fall from a height at the same time and always hit the ground at the same time. The falling speed of the iron balls has nothing to do with the weight of the iron balls. Galileo was only 25 years old at the time and was already a professor of mathematics. He announced the results of the experiment to the students and announced that he would conduct a public experiment on the Leaning Tower of Pisa.

The news spread quickly. On that day, many people came around the Leaning Tower to see who was the winner on this issue. Is it the ancient philosopher Aristotle or the young mathematics professor Galileo? Some said: "This young man is so bold and wants to find fault with Aristotle!" Some said: "He won't be stubborn anymore. The facts are ruthless and will make him lose face!"

Galileo appeared on top of the Leaning Tower. He holds a 10-pound iron ball in his right hand and a 1-pound iron ball in his left hand. The two iron balls were released at the same time and fell from the air. After a while, people around the Leaning Tower couldn't help shouting in surprise, because everyone saw two iron balls landing at the same time, just as Galileo said. Only then did everyone realize that not everything a great philosopher like Aristotle said was right.

Teaching Analysis of Lesson 25 "Two Iron Balls Landing on the Ground at the Same Time" in Volume 2 of Chinese Language for Grade 4

"Two Iron Balls Landing on the Ground at the Same Time" is to cultivate students to be good at analysis and dare to make breakthroughs A good textbook with a scientific attitude towards superstition and the courage to practice. However, it is not an easy task to make the spirit of Galileo, the great Italian scientist in the 17th century, deeply moved and understood by children living in China today. Based on the characteristics, emphasis and difficulties of this article, combined with the students' psychological characteristics and life reality, I gave full play to the leading role and greatly improved the efficiency of classroom teaching.

I think the most successful aspects of undergraduate teaching are: First, grasp the requirements and design teaching methods. Before the students accepted the learning task, I made it clear: to study Lesson 21, we must understand the steps Galileo used to successfully reach the conclusion that "two iron balls touched the ground at the same time." Because the requirements are clear, students can study in a targeted manner. In view of the characteristics of this article, I creatively combined the "exercise training method" and the "situational prompting method", that is, using the after-school exercises as the outline, making full use of images to create specific and vivid scenes, so as to achieve the ultimate goal. Best teaching effect. The second is to stimulate interest and mobilize enthusiasm.

As the teaching content deepens and changes, I sometimes ask questions, sometimes demonstrate objects, sometimes illustrate on the blackboard, sometimes read texts to myself, sometimes perform roles, and sometimes consolidate exercises. The teaching methods are novel, varied, and sufficient

Mobilizes students' enthusiasm, makes them love and enjoy learning while full of interest, high spirits, and high learning efficiency. The method of creating specific and vivid scenes enables it to achieve the best teaching effect.

Teaching Suggestions for Lesson 25 "Two Iron Balls Landed Simultaneously" in Volume 2 of Chinese Language for Grade 4

1. Before class, if possible, students can be asked to collect information about Aristotle Biographies or pictures of the lives of De and Galileo, a preliminary understanding of the background of the events, and a certain perceptual understanding of the characters.

2. Teachers can refer to the following teaching ideas for teaching:

First, use the inspiration obtained as the main line to organize students to conduct exploratory reading:

That is Stick to the last sentence of the text - only then did everyone realize that not everything a great philosopher like Aristotle said was right. Understand why people expressed such emotion at that time. Seize the "talent" and "original", let students fully read, outline, annotate, and then communicate with the whole class, and gradually and deeply understand Galileo's scientific attitude of not being superstitious about authority, daring to ask questions, and persistently pursuing the truth. Encourage students to speak boldly about the revelations they have received. For example, they should also talk about science and evidence when they doubt; they should have enough courage to insist on the truth; many scientific innovations and inventions are born in the criticism of authority. Then let students talk about their experience of this sentence based on actual practice.

The second is to use characters as clues to organize students to read:

Aristotle, the highly respected Greek sage, said what people regard as unquestionable truth. It was once said that the falling speed of two iron balls is proportional to their mass; Galileo, a young professor, went from doubting Aristotle to repeatedly verifying Aristotle's words and then to public experiments; from being ridiculed and ridiculed by people, he finally ended up with two The fact that the iron balls hit the ground at the same time made people change their minds.

In the process of getting to know the characters, be careful not to exalt one thing and suppress the other. You can supplement the information. For example, Aristotle is very knowledgeable and is known as the "most learned figure" in ancient Greece *** "Selected Works of Marx and Engels" Volume 3, page 59***, and is the founder of formal logic. He has made outstanding contributions in medicine, philosophy, physics, aesthetics and psychology. Such authority should be respected by people, but should not be blindly superstitious.

3. When guiding students to experience the great spirit of Galileo, they should pay attention to the understanding of the text content:

First, let students understand the social background of the time, that is, the worship of authority in the scientific community and the Follow blindly. It can also be added that in the 16th century, Bruno was burned alive in the Roman Forum by the Pope for insisting on the truth of the "heliocentric theory". Galileo questioned authority not only to face people's ridicule, but also to endure huge mental pressure and risks, further understanding of Galileo The great spirit of having the courage to devote oneself to science.

Second, we must combine the words and deeds of the characters to make the image of Galileo vivid. Galileo's questioning of Aristotle's views was not a simple and hasty suspicion, but based on correct assumptions and through rigorous logical reasoning, he came to two opposite conclusions, which shows his scientific attitude of seeking truth from facts. The public experiment on the Leaning Tower of Pisa, with convincing facts, effectively impacted the blind worship and superstition of the time, which is of great significance.

4. Galileo’s doubts about Aristotle’s views are difficult for students to understand. Students can fully read the text, discuss in groups, and report in a simple and easy-to-understand way:

For example:

10 1lt; 10 Two iron balls are tied together. The slower one will drag the faster one, and the falling speed should be slower than the 10-pound iron ball.

10 1gt;10 The two iron balls tied together weigh 11 pounds as a whole, and they fall faster than the 10-pound iron ball.

You can also use diagrams or demonstration courseware to help students understand.

5. The main feature of this article is that it uses typical examples to express the characters’ qualities, and the characters’ psychology, actions and language descriptions are very vivid. Students should be encouraged to try to practice language practice in reading, speaking and writing. Activity. For example, based on full reading, illustrations can be combined to allow students to imagine situations and talk about what people would say and do when Galileo came down from the Leaning Tower of Pisa after his experiment and people surrounded him. Through the description of the words and deeds of the characters, we can further understand Galileo's scientific attitude of respecting authority without blind obedience and persistent pursuit of truth.

6. Instruct students to read the text emotionally:

It is necessary to read the questions and analytical thinking in Galileo's psychological activities in the correct tone; for the language of people's discussions, it is necessary to read There are emotional changes, such as the defense of authority in the fifth natural paragraph, dissatisfaction, ridicule and blame for Galileo; and the sixth natural paragraph, there is surprise and excitement in the sudden enlightenment.

7. Instruct students to learn new words on their own, paying attention to the correct pronunciation of polyphonic words in this article:

With ***zháo***地, more***gēng ***Correction, ***dí*** correct, daring ***wéi***; to distinguish "discrimination braid", you can use the following jingle: Distinguish carefully point by point, and there are words in the middle to argue, Find silk thread and tie it into a small braid.

The optional questions after class can guide interested students to look for them and then copy them down. The antonyms in the article are: fast──slow, left──right, light──emphasis on right──wrong.

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