Siheyuan: The Legacy of Wei Wu

Chapter 164 Buoyancy
Put the watermelon in a place where the stream is slightly deeper and blocked by stones, and use the temperature of the stream to make an iced watermelon.

Besides watermelon, Ding Qiunan asked Wang Hao to take out several other fruits, put them in the same place where the watermelon was placed, and ice them with stream water.

Besides fruits, Ding Qiunan asked Wang Hao to take out some other snacks from the space.

Since Ding Qiunan found out about Wang Hao's system space yesterday, now he regards Wang Hao as a human body warehouse.

As long as she wants to eat something, or something else, as long as it is food, she wants Wang Hao to take it directly from the space.

Of course, Ding Qiunan still pays attention to the surrounding environment, if there are strangers around, then she will definitely not let Wang Hao take things from the space.

After all, we still have to pay attention to the impact.

After taking out all the things, Ding Qiunan took Wang Hao and started to walk towards Ding's father, Ding's mother and Yu Li.

"Mom and Dad, Sister Li, Wang Hao is here. Let's freeze some fruit in the small puddle below. Let's eat some fruit later and play after a rest." Ding Qiunan walked to her parents and said to several people.

"Mom, I want to eat watermelon! You just called auntie and the others to eat fruit, but you didn't call me, you're biased!" Little Wang Ye said to Ding Qiunan immediately after hearing what Ding Qiunan said.

"Oh, my dear son, how could mom forget you! Your big watermelon has been put on ice for you a long time ago, let's eat it later, look at your pouty mouth, no one can forget when mom forgets I lost my precious eldest son!"

Ding Qiunan saw his son pouted, pretending to be angry, hugged little Wang Ye fondly and said softly to him.

"Dad! Mom!" Wang Hao and Ding Qiunan's parents greeted each other and walked slowly to Yu Li's side.

"Sister Li, what are you doing with so many small fry, they haven't grown up yet, and they can't be eaten!"

Wang Hao walked to Yu Li and said to Li.

"No, isn't this what Xiao Ye wants to play!" Yu Li looked at Wang Hao, then turned to look at Xiao Wang Ye, and said with a smile.

"Okay, are you having fun? Are you tired?" Wang Hao asked Li in a low voice.

"I'm not tired. I've had a lot of fun here these two days. Don't worry about me. Just take care of Qiunan and the others. I can take care of Hao himself!" After Yu Li answered Wang Hao in a low voice, she went on her own Wang Hao walked downstream as they said.

Ding Qiunan and the others also followed behind Yu Li and walked towards the place where she and Wang Hao had iced the fruit just now.

When he arrived at the place, little Wang Ye saw all kinds of fruits in the pool, and immediately shouted: "Wow~ Mom, where did you and Dad conjure so many fruits, and there are delicious ones!"

"Your father drove outside to get it for you. Feel if it's cold. Let's eat it when it's cold." Ding Qiunan said to the bewildered little Wang Ye.

"Ah?! Daddy has worked hard!" Little Wang Ye said to his father, Wang Hao, in his sincere and immature voice.

"It's okay, dad doesn't have to work hard, let's eat quickly." Wang Hao touched the head of his son Wang Ye with his hand, and said something doting.

"Ok!"

After Xiao Wang Ye happily answered, he quickly went into the water to touch the watermelon he wanted to eat the most.

"It's cold, it's cold, Dad." Little Wang Ye shouted to Wang Hao cheerfully.

"Then try to see if you can hold it. If you can hold it, just take it out and let's open it and eat it." Wang Hao said to little Wang Ye with a smile.

Hearing his father's words, little Wang Ye was eager to try. He put his little hands into the water, spread his hands out, and prepared to try to pick up the watermelon in an embrace.

It's a pity that little Wang Ye overestimated his strength, or underestimated the weight of the watermelon.

After trying many times, he could only hold the watermelon until it was about to leave the water.

There is no record of holding a watermelon out of the water once.

This situation made little Wang Ye very confused, so he asked his father Wang Hao aloud: "Dad, why can I hold a watermelon in the water, but I can't hold it when it is out of the water?"

"Because water has buoyancy, watermelon will be lighter when you are in the water, but when out of the water, the buoyancy of the water will naturally disappear, and you will not feel the buoyancy of the water. The watermelon will naturally become heavier. !"

When Wang Hao heard his son Wang Ye's question, he answered it patiently.

"What is buoyancy? Why is there buoyancy in water?"

Little Wang Ye seems to be like a book of [-] whys, and he will keep asking questions that he doesn't understand or don't know.

"Buoyancy refers to the pressure difference between the upper and lower surfaces of an object in a fluid (including liquid and gas).

A long time ago, in 245 BC, there was a Scientologist called Archimedes, that is, he discovered the principle of buoyancy.

He defined the buoyancy as F up - F down, and the calculation formula can be written as ρ liquid gV row.The force lifted up by the liquid or gas on an object immersed in a liquid or gas is called buoyancy.

As for why.This is a bit complicated to say, and I will explain it to you slowly.

You see, objects floating on the surface of the fluid or submerged in the fluid are subject to the upward combined force of the hydrostatic pressure in all directions.Its magnitude is equal to the gravity of the fluid displaced by the object.

Also, in a liquid, the pressure is different at different depths.

In addition, the depth of the upper and lower parts of the object immersed in the liquid is different, so the upward pressure of the liquid on the lower part of the object will be greater, and the pressure will also be greater. It can be proved that the buoyancy is equal to the difference between the upward and downward pressure of the liquid on the object. Difference.

For example, if the gravity of a stone is greater than the weight of the same volume of water, it will sink to the bottom of the water.

The weight of the driftwood or hull is equal to the weight of the water displaced by the submerged part, so it floats on the water.

The weight of the balloon is less than the gravity of the same volume of air, that is, the buoyancy is greater than the gravity, so it will rise.

This kind of force that is immersed in water or air and is lifted up by water or air is called "buoyancy".

For example, the watermelon you just picked up from the water was lighter before it left the water than after it left the water, because the watermelon is buoyant.

And not only water, but all liquids, such as alcohol, kerosene, or mercury, have a buoyant force on objects immersed in it.

All liquids are the same.Of course, objects immersed in a gas (which, like liquids are fluids) are also subject to buoyant forces.

Just like the balloon I just gave you as an example, it only rises due to the buoyancy of the gas.

Can you understand that? "

Wang Hao babbled a lot to his son Xiao Wang Ye, but the expression on his son Xiao Wang Ye's face became more and more bewildered.

When Wang Hao said something later, little Wang Ye was already in a state of bewilderment!

(End of this chapter)