What was the experiment with the magic button?

Difficulty:

Methodology: This is a very interesting little experiment to do. Have a button on your shirt ready. Then pour the carbonated drink (containing CO2) into a glass. Put the button into the cup again, and the button immediately sinks to the bottom of the cup.

After 2 minutes, speak softly to the clasp; "Come on, come on! Hurry up! The clasp slowly floated from the bottom of the cup into the water.

After a while, he said, "Okay, you can go back." The clasp immediately returned to the bottom of the cup obediently. How amazing!

Extension of knowledge: Practical anything small and light can be used for this experiment. When the button sinks to the bottom of the cup, the carbon dioxide bubbles immediately gather on the button, when the buoyancy of the carbon dioxide bubbles in the water is greater than the gravity of the button, the button will slowly float to the water, to the surface of the water, the carbon dioxide bubbles gradually go to the air, when the weight of the button is greater than the buoyancy, it sinks to the bottom of the cup.

Because the drink contains a large amount of carbon dioxide gas, after the button returns to the bottom of the cup, carbon dioxide bubbles will accumulate on it, so the above phenomenon appears again. Until the carbon dioxide gas is almost gone.

If you want to make the experiment work well, you need to do it repeatedly and grasp the time when the button is up and down. This is important.

Through simple experiments with common objects, the buttons disappear from sight, and the baby understands that light refracts when passing through different media.

Spinning Button Procedure:

1: Find a large buckle or a round piece of cardboard with a hole in it.

2: Thread a 100---115cm long rope and tie knots at both ends.

4: Pull the rope taut so that the clasp or cardboard rotates in the opposite direction.

5: Loosen the rope again and let the clasp or cardboard rotate in the direction of the initial hand swing.

6: Pull and loosen without stopping, so that the clasp or cardboard rotates rhythmically.

The energy conversion process: just the rope does work on the mouth, there is no conversion of kinetic energy and potential energy, but if it is accurate to say that kinetic energy is converted into internal energy (internal energy is thermal energy).

Energy conversion in the spinning button experiment: the button ascent process: kinetic energy is converted into gravitational potential energy and heat energy generated by friction with air. Button Descent Process: Gravitational potential energy is converted into kinetic energy and heat energy produced by friction with air.

Energy can neither be produced nor disappear, energy conversion refers to the transformation from one form to another or from one object to another, except that the universe can make energy disappear.

.Pour some hot water into a plastic cup. The hot water expands the air in the cup.

2.Blow up the balloon and pour some cold water over the surface of the balloon.

3.Pour out the water from the cup and place the cup tightly against the lower part of the balloon.

4.After a minute, lift the balloon and the balloon will grab the cup and lift it up!

18* Motherly affection.

1. Interpretation of teaching materials.

1.The text is brief.

This text tells the story of a poor and hard-working mother, who did not hesitate to give money to "me" to buy "The Young Guard" despite the dissuasion of her colleagues.

The text begins with the fact that "I" want to buy a copy of "The Young Guard". Thinking of "losing one's soul all day long" shows the extreme desire. However, with the price of more than one yuan and the poor family background, it is difficult to realize "my" wish.

Next, write that my mother gave me money to buy the book. This part is the focus of the whole article. The mother's appearance, language, movements, and demeanor are described.

Mom, who works in a corner of the workshop, has a "thin back bent, and her head is very close to the sewing machine." Skinny mother! The mother dug into her coat pocket, pulled out a crumpled roll of wool tickets, and counted them with her cracked hand.

Poor mother! When the mother had finished speaking, she sat down again, bent her back again, and laid her head on the sewing machine again, and immediately fell into a busy ...... again"Toiling mother! However, it was this mother, when a colleague thought that "I" was asking for money to buy idle books and dissuaded her from giving me money, my mother said:

I'm glad he loves to read." Reasonable mother. These places highlight the kindness and kindness of the mother, and express the deep respect and love for the mother.

In the end, talking about "I" finally has the first full-length book**.

After reading the text, everyone will be deeply moved by the love of motherhood. What an unforgettable impression this ordinary mother, hard mother, poor mother, and deep maternal love shown in this little thing of daily life.

In studying this text, we should focus on guiding students to experience the greatness of ordinary mothers, feel the great maternal love, and stimulate the thoughts and feelings of loving mothers through sentences that describe the appearance, language, movements, and demeanor of mothers.

2.Word and sentence parsing.

1) Comprehension of sentences.

I don't think I have the right to use that money to buy anything else, either for myself or for my mother. ”

This sentence is to say that it is not easy for my mother to earn money and her family is so difficult, but she did not hesitate to give me money to buy books, so that I can satisfy my strong desire to study. If I use that money to buy other things, I'm really sorry for my mother, and I'm sorry for my mother's deep love for her son.

2) Comprehension of words.

Lost Soul describes the appearance of extreme panic and abnormal movement.

Deafening ears are shaking to the point of deafness. Described as loud.

Cracking **Cracking due to cold dryness.

2. Author Introduction:

Liang Xiaosheng (1949—)** home. A native of Rongcheng, Shandong. In 1968, he went to work in the Great Northern Wilderness.

He graduated from Fudan University in 1977. He has worked in Beijing Film Studio and Beijing Children's Film Studio. The main works are:

the short story ** "Father"; Novella** "There's a Snowstorm Tonight"; Long-form ** "Snow City", "Year Rings", etc. ** Collection of "Heavenly Love", "This is a Magical Land", "Fireworks in the World", "Birch Bark Lampshade", "Black Button". "Mother's Love" was selected as a primary school Chinese textbook.