Scientific knowledge of crow drinking water 1. What is the mathematical principle of crow drinking water?

Solution, get:

The mathematical principle of crow drinking water is: put stones into the water to make it bigger,

There is some water in the bottle with a tight mouth. The crow wants to drink, but his mouth can't reach the water in the bottle. So the crow took some pebbles and put them in the bottle. The height of the water in the bottle rises with the increase of pebbles, and the crow drinks the water. But before he could quench his thirst, the water in the bottle fell to a height beyond the reach of the crow, so the crow had to grab some stones and put them in the bottle, and the water rose again. The crow finally drank enough water and flew away.

Experiment 1

Experiment 1(4 sheets) First, add half a glass of water to the glass. (Note: the water is more than half of the glass)

Step two, put a stone in the cup.

As soon as the stone was put into the cup, it was found that the water was also lifted. The yellow label is the water level when the stone was not put just now. )

Finally, add the stone until the water rises to the top of the cup. At this time, the crow can drink water.

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As we know, the volume of a cuboid is equal to the length times the width times the height, and the volume of a cube is equal to a cube with long sides. But have you ever thought about how to find out the size of an egg?

Faced with this problem, you may be at a loss, because the shape of eggs is irregular and there is no ready-made formula available.

In fact, this question is also very simple. You must have read the article "Crows Drink Water". The crow found water in the bottle, but the bottle mouth was too small and the water level was too low. what should he do ？ The clever crow found pebbles around, so he put them in a bottle. Every time a pebble is thrown, the water surface will rise once; The bigger the stone is thrown, the higher the water surface rises. This is because the stone has a "volume" and occupies a certain space, so it "squeezes" water equal to its volume. In other words, the volume of "squeezed" water is exactly equal to the volume of the stone thrown.

The volume of a stone is difficult to calculate because its shape is very irregular. If we can calculate the volume of water it squeezes, things will be much easier. As long as we use a cuboid vessel, it is easy to calculate the volume of squeezed water.

Suppose that the bottom of this rectangular vessel is a square with a side length of 4 cm, and the water level rises by 2 cm after the stone is placed, then the volume of the stone is 4*4*2=32 (cubic centimeter). When you get here, you will shout happily, "Then I want the size of an egg, too."

The cleverness of the crow is that it makes the water in the bottle rise with the help of pebbles, so as to drink the water it wants to drink.

The cleverness of human lies in the ingenious idea of "equivalent substitution" from drinking crow's water.

2. The experiment of crows drinking water

New discovery: full of stones, crows may not drink water.

Record:

Put the stones into the bottle piece by piece. The higher the base, the higher the water will rise ... When the 30th stone was put into the bottle, something unexpected happened-the water level stopped rising, but the stone was even higher than the water level until the bottle was full of stones and the water level did not rise to the mouth of the bottle. "Crows cannot drink water!"

"The cobblestones are irregular in shape and there are many gaps between them. A lot of water is hidden in the cracks. On the other hand, there are countless tiny potholes on the seemingly smooth cobblestone surface. In dry conditions, these pits are filled with air, and when they are thrown into the water, pebbles themselves will absorb a small part of the water. If there is too little water in the bottle, some of the gaps between the stones are hidden, and some of the pebbles themselves are absorbed, so the crow will naturally stop drinking water. "

Are you satisfied with the above answers?

3. What is the main content of crow drinking water?

original text

A crow was thirsty and looked for water everywhere. The crow saw a bottle filled with water. But there is not much water in the bottle, and the mouth of the bottle is small, so the crow can't drink water. What should we do?

The crow saw that there were many pebbles beside him, so he thought of a way.

The crow put pebbles into the bottle one by one. The water in the bottle rose gradually, and the crow drank the water.

learning target

Crow drinks water (text) 1, knows nine new words such as "Wu, crow" and can write "Ke, Shi".

2. Read the text correctly and fluently. Read aloud and experience the changing process of "crows are in a hurry to find water-can't drink water-try to drink water-drink water".

3. Know the truth of observing carefully and thinking seriously when encountering difficulties.

4. Teaching plan and reflection of "How do crows drink water" in kindergarten science class.

Design intent:

"The crow drinks water" is a well-known story. Children all know through stories that crows drink water by adding stones to a bottle filled with water to raise the water level. But is this the case? Is it related to water quantity? Does it have anything to do with different materials? I think this can let children know the correct answer through hands-on operation, instead of just relying on stories to know the result, so I chose a content for children to conduct small experiments and learn the truth through exploration.

Activity objectives:

1. Through calculation, it is known that adding stones and sand to a bottle filled with water can raise the water level.

2. Through active exploration, it is found that whether crows can drink water is related to the amount of water and the different materials.

3, study group cooperation and exploration, experience the fun of cooperative learning and communication with peers.

Activity preparation:

1, children are already familiar with the story of crows drinking water.

2, a group of four people: three bottles in each group, less water in the bottle, half a bottle, half a bottle (two for each person), a basin of stones, a basin of sand, three chopsticks, three spoons and three funnels.

3. A set of experimental recording paper.

Activity flow:

First, ask questions to stimulate interest.

Teacher: Children, just now we heard the story of a crow drinking water. Do you know how crows drink water?

Summary: It turns out that after adding stones to the bottle filled with water, the water level rose, so the crow drank water.

Teacher: The teacher prepared three bottles of water and stones today. Please look at the difference between these three bottles of water.

Teacher: Did you find a blue line on each bottle? This is the water mark. If you add stones, the water can rise to the water level, which means the crow can drink water.

Teacher: There are stones in these three bottles of water. Can crows really drink water? (children guess)

Teacher: Then let's do a little experiment! Complete the experiment in groups of four children. Three children each take a bottle to do the experiment, and the other child is responsible for observing and recording the experimental results. Later, you can discuss who does the experiment and who takes notes.

Teacher: How do you record the recorded children?

Teacher: Then we will use the methods of "√" and "*" to put "√" in the box behind the bottle that can drink water, and "*" if not. During the experiment, we will observe while doing the experiment and see what we will find. When a group of children have finished their experiments, please put the experimental bottles on the front table, ok? Now, let the children find a table and start the experiment without moving the chair.

Second, the child's first operation experiment, the teacher tour guidance.

Teacher: Please give the recording paper to the group of teachers who finished the experiment, and the other children will take the bottles of your experiment to the front table.

Teacher: (looking at the record paper with the children) Let's look at their achievements on the record paper.

Teacher: Please tell the children: What did you add to the bottle? What did you find? (Please talk about individual children)

Teacher: Well, think about it. Why didn't the red water reach the water level with so many pebbles, and the crow still couldn't drink the water?

Third, the second experimental exploration, the teacher observed and guided.

Teacher: Is that true? Let's do the second experiment. Still those three bottles of water, the content is different. Let's do this experiment with sand instead of stone.

Teacher: Before the experiment, the teacher still has some requirements. Please listen carefully: same as before. Because the sand is fine, the teacher invited a small funnel, sand and chopsticks to help. Be careful not to spill the sand. Pay attention to safety when using chopsticks. Moreover, this time, please ask the children to get the information themselves. The teacher has arranged it for everyone. Please ask the children in charge of recording to get the sand. The other children each took a bottle and started the experiment.

Teacher: Tour observation and guidance until the experiment is completed.

Teacher: Please give the recording paper to the teacher. The other children put the bottles on the front table as before. Be careful not to splash water and walk slowly.

Teacher: Let's look at the recording paper together. Let the children say: What did you put in what bottle? What did you find? (Please invite individual children)

Teacher: Let's have a look. What is the difference between the results of the first recording paper and the second recording paper?

Teacher: Why can't adding stones to red water just now make the water rise to the water level? Now it's ok to add sand? Please talk to the child next to you.

Teacher: (showing pictures) Let's ask Xiao Tu to do us a favor and have a look. Is it the same as the child said?

Teacher: Do you find any difference between them?

Teacher: Yes! There is a big gap between stones. After adding stones, the water in the red water bottle with little water will flow into the gap, so the crow can't drink water. The sand is fine and the gap is small. Although water also flows into the gap, it can still rise to the water level, and crows can still drink water.

Teacher: There are still many things in our life. Please try it with other children in the class after class and see what new discoveries will be made, ok?

5. composition crow drinking water experiment: one third of the water.

enlighten

A crow may not drink water, even if it is full of stones.

Record:

Put the stones into the bottle piece by piece. The higher the base, the higher the water will rise ... When the 30th stone was put into the bottle, something unexpected happened-the water level stopped rising, but the stone was even higher than the water level until the bottle was full of stones and the water level did not rise to the mouth of the bottle. "Crows cannot drink water!"

Pebbles are irregular in shape, with many gaps between them, and there is a lot of water hidden in the gaps. On the other hand, there are countless small pits on the smooth surface of pebbles. In dry conditions, these pits are filled with air, and when they are thrown into the water, they will also absorb a small part of the water. If there is too little water in the bottle, the gaps between the stones are hidden, and the pebbles themselves absorb some, so crows naturally won't drink water. "