In August and autumn, the wind roared, rolling up the physics knowledge related to the triple thatch

c The greater the flow velocity, the smaller the pressure, because the wind is flowing, so the pressure outside the house becomes smaller, and the wind inside the house is very small, the pressure changes little, it can be ignored, the pressure inside and outside the house is the same, and now the pressure outside the house becomes smaller, and the pressure inside the house becomes relatively larger, so the effect of "August and autumn high wind roars, rolls up the triple thatch on my house".

Because the pressure inside the house is actually constant, it is the pressure outside the house that becomes smaller, so C is chosen

cThe faster the surface flow velocity, the lower the pressure, so when the air above is blowing, the velocity is fast and the pressure is small. The velocity of the air flow below (in the house) is the same, so the pressure here is also the same. Originally, the two forces were balanced, and the outside was reduced and the inside was unchanged, of course, the resultant force was outward.

c The thatch on the roof of the thatched hall is subjected to a decrease in downward pressure.

In physics, the higher the speed, the lower the air pressure, the strong wind blowing on the roof, the wind speed is high, and the indoor space in the house obviously does not blow strong winds, and the air pressure is higher than that above the house. Form an upward lifting force.

The pressure in the place where the flow velocity is large is small, and the change in the pressure in the house can be ignored, so the downward pressure of the thatch is small, and because the force area is unchanged, so"The thatch on the roof of the cottage is subjected to less downward pressure"

Force can change the state of motion of an object.

The higher the gas velocity, the lower the pressure.

The action of force is reciprocal.

Sound is produced by vibrations.

Howl of rage. It is formed because the wind blows through the windows, the cracks in the doors, and the gas flows through the surface of the object at high speed.

Roll up the triple grass on my house"

Refers to rolling up the triple grass on the house?

In physics, the higher the speed, the lower the air pressure, the strong wind blowing on the roof, the wind speed is high, and the indoor space in the house obviously does not blow strong winds, and the air pressure is higher than that above the house. Form an upward lifting force.

Bernoulli's Law; The pressure is small when the flow rate is large. Due to the small edge velocity of the airflow.

The pressure is strong, and the pressure pushes the ball back into the air stream.

According to the knowledge points that the pressure is small in the place where the gas flow rate is large, the air flow rate on the roof is large and the pressure is small, and the gas flow rate in the house is slow and the pressure is strong, so that the pressure difference between the inside and outside of the house is formed, that is, the pressure inside the house is stronger than the pressure outside the house, so the roof is rolled up by the wind.

1: The greater the gas velocity, the lower the pressure.

2: The action of force is mutual.

It's autumn.

Autumn is one of the four seasons of "Spring, Summer, Autumn and Winter". In China, the "beginning of autumn" of the 24 solar terms is traditionally used as the starting point of autumn. Autumn means that rainfall, humidity, etc. tend to drop or decrease, and everything in nature begins to grow from lush to mature.

According to the modern scholar Zhang Baokun's average temperature, the average temperature is divided into four seasons, and the index is that the period when the average temperature is lower than 10 is winter, the period higher than 22 is summer, and the period of 10 22 is spring and autumn.

In China, the "beginning of autumn" of the 24 solar terms is traditionally used as the starting point of autumn. Entering autumn, it means that rainfall, humidity, etc. tend to drop or decrease. In nature, the yin and yang energy begins to change, the yang energy gradually retreats, the yin energy gradually grows, the climate changes from hot to cold, and everything grows with the cold and gradually declines.

According to modern meteorology, the autumn in the north temperate zone is on August 23 (summer heat) and November 22 (light snow); Autumn in the southern temperate zone falls on February 19 (Northern Hemisphere rain) and May 21 (Northern Hemisphere Lesser Man).

At present, the division of the four seasons in China is often divided according to the temperature change, and the division of "waiting for average temperature" by modern scholar Zhang Baokun is adopted. According to the average temperature method, there are two main criteria for judging the beginning of autumn: first, the average daily temperature between 10 22 for five consecutive days can be regarded as autumn and become a "simple standard"; The second is:

The sliding average temperature of 5 consecutive groups was below 22. A set of sliding average temperatures refers to the average temperature of the day plus the average temperature of the previous four days divided by 5 to obtain the 5-day sliding average temperature, which is the "sliding mark".

In August and autumn, the wind roared, rolling up the triple thatch on my roof. Mao flies across the river and sprinkles the suburbs of the river, the high one hangs on the long forest tops, and the lower one floats to the sinking pond pass. The children of Nancun bullied me for being old and powerless, and I could endure being thieves on the other side.

openly hugged the grass into the bamboo, his lips were dry and he couldn't breathe, and he came back and sighed to himself. The Russian wind sets the clouds and ink, and the autumn desert turns to darkness. The cloth has been cold like iron for many years, and Jiao'er is wicked and cracked.

There is no dry place in the bedside room, and the rain feet are not cut off. Since the mourning and lack of sleep, the long night is wet.

It is said that the seasons of spring, summer, autumn and winter change together, so there will be so.

In August, the autumn wind roared angrily, and the triple thatched house on the core of my house" is from the Tang Dynasty poet Du Fu's "Song of the Thatched House Broken by the Autumn Wind".

Full text: The high wind roared in August and autumn, rolling up the triple thatch on my house. Mao flies across the river and sprinkles the suburbs of the river, the high one hangs on the long forest tops, and the lower one floats to the sinking pond pass.

The children of Nancun bullied me for being old and powerless, and I could endure being thieves on the other side. openly hugged the grass into the bamboo, his lips were dry and he couldn't breathe, and he came back and sighed to himself.

The Russian wind sets the clouds and ink, and the autumn desert turns to darkness. The sail town has been digging cloth for many years, and the poor Jiaoer is evil and cracked. There is no dry place in the bedside room, and the rain feet are not cut off. Since the mourning and lack of sleep, the long night is wet.

There are tens of millions of mansions in Ande, and the poor people in the world are happy! The wind and rain do not move, and it is as safe as a mountain. Alack! When I suddenly see this house in front of me, it is enough for me to freeze to death!

Du Fu's poems in the Tang Dynasty were written from Du Fu's poems in the Tang Dynasty, and the thatched hut was broken by the autumn wind. This poem recounts the author's thatched hut and shack ruler was broken by the autumn wind and the painful experience of the whole family being drenched in the rain, expressing his inner feelings, reflecting the poet's lofty ideological realm of worrying about the country and the people, and is a model work of distress in Du's poems.

Wind Fury: Air vibrations produce sound (sound is produced by vibration) Roll my house on the triple source of the grass: force can change the state of motion of objects.

The velocity of the fluid is greater and the pressure is smaller, so the thatch moves upwards.

You can hear the roar of the wind: sound propagation requires a lack of media.

Wind Fury: The propagation of sound is essentially the vibration of the medium, and the greater the amplitude of the medium, the louder the sound.

Volume: Rotation produces centrifugal force, which causes the air in the center of the cyclone to overflow outward, forming a pressure difference, which in turn forms an upward lift force that makes the thatch fly high.

(1) "Wind Fury": The wind speed is very high, and the force is very strong.

2) "Volume": When the wind blows, the air velocity increases, the pressure decreases, the pressure inside the house is stronger than the pressure outside the house, and the roof moves under the action of pressure difference.

It refers to the difference in gas pressure between the inside and outside of the thatched house.

In August and autumn, the air velocity above the thatched roof accelerates, the air pressure decreases, and the air pressure below is greater than the air pressure above, then the thatch is lifted and swept away by the wind.

Similarly, the cyclist's hat was suddenly swept away by a strong wind;

Even after the gale, the entire roof of some houses was swept away.

The fourth section of Chapter 14 of Grade 9 Physics "The Relationship between Fluid Pressure and Flow Velocity".

The air flow rate on the upper surface of the thatched hut is fast, the pressure becomes smaller, and the pressure on the lower surface is stronger than that on the upper surface, so the "thatch" is swept away.

Windfury: Force?

Volume: Direction? tree

The autumn wind in August blew the three layers of thatch on my house.

The metaphor is a bad situation, expressing the author's helpless sadness and ......

This is a poem in the Tang Dynasty poet Du Fu's "Song of the Thatched House Broken by the Autumn Wind". Roughly speaking, the wind was so strong that it blew away several layers of thatch on top of the house.

It describes the poor family conditions and the state of poverty. There is another sentence in the back, "The children of Nancun bullied me for being old and powerless, and An Neng was a thief on the other side" This sentence is written on the surface that a group of children picked up all the thatch from his house, but in fact, it shows that most of the people's lives are so hard.

In this way, it sets off the last sentence: "There are tens of thousands of mansions, and the poor people in the world are happy." ”

In the autumn of August of the lunar calendar, the weather is not good, and the wind is very strong, blowing away all the thatch covering the huts!

The August sky was crisp, but suddenly a howling wind blew and swept away the three layers of thatch on my house.

Du Fu's "Song of the Thatched House Broken by the Autumn Wind" The high autumn wind roared angrily in August, rolling up the triple thatched on my house. Mao flies across the river and sprinkles the suburbs of the river, the high one hangs on the long forest tops, and the lower one floats to the sinking pond pass. The children of Nancun bullied me for being old and powerless, and I could endure being thieves on the other side.

openly hugged the grass into the bamboo, his lips were dry, and he sighed when he returned. The Russian wind sets the clouds and ink, and the autumn desert turns dark. The cloth has been cold like iron for many years, and Jiao'er is wicked and cracked.

There is no dry place in the bedside room, and the rain feet are not cut off. Since the mourning and lack of sleep, the long night is wet. There are tens of millions of mansions in Ande, and the cold people in the world are happy, and the wind and rain are not moving.

Alack! When I suddenly see this house in front of me, it is enough for me to freeze to death!

Du Fu: The thatched hut is broken by the autumn wind.

The thatched hut is broken by the autumn wind.

Du fu. In August and autumn, the wind roared, rolling up the triple thatch on my roof.

Mao Fei crosses the river and sprinkles the suburbs of the Yujiang River, the higher one hangs on the long forest tops, and the lower one floats to sink the pond pass.

The children of Nancun bullied me for being old and powerless, and I could endure being thieves on the other side.

openly hugged the grass into the bamboo, his lips were dry and he couldn't breathe, and he came back and sighed to himself.

The Russian Zen touches the wind and sets the clouds and ink, and the autumn desert turns dark.

The cloth has been as cold as iron for many years, and the arrogant child is evil and cracked.

There is no dry place in the bedside room, and the rain feet are not cut off.

Since the mourning and lack of sleep, the long night is wet.

There are tens of millions of mansions in Ande, and the cold people in the world are happy, and the wisdom of the rock is not moving, and it is as safe as a mountain!

Alack! When I suddenly see this house in front of me, it is enough for me to freeze to death!