How did you, a prisoner on death row, become an important weapon of the country? Yecheng Gao Weiming

"This……"

After hearing this, Song Xiaocheng was speechless.

Yes!

How can others help you?

If you can't even guarantee your own life, how can you care about the life and death of others?

Song Xiaocheng had no choice but to turn around and seek help from his team members, or even directly go to his younger sister Song Xiaoxuan.

Your brother is about to die, and you really don’t care?

Unexpectedly, when he looked up again, everyone's eyes were focused on him and Watanabe Ryuichi.

Everyone heard the conversation between the two clearly, and the same question arose in their minds.

Ryuichi Watanabe, judging from your appearance, you must be an elite in physics.

It should not be difficult to calculate the length of the elastic cord using Newton's second law and Hooke's law.

Why will you die, and all of us die?

Facing everyone's questions, Watanabe Ryuichi sighed.

"Because of the height, everyone."

"I know you're all busy calculating, and it would be rude to interrupt you."

"But I'm sorry, I really can't solve the problem of the height from here to the water surface. If I make a mistake, the consequences will be fatal. I have no choice but to come here to seek..."

As he spoke, Watanabe actually looked at Song Xiaoxuan, Chen Ziqi, Wang Luxiang and others.

"Seeking your help."

He held out his hand again, with his usual gentle manner.

"I looked at all the participants' information yesterday and learned that you all graduated from the best universities in Dragon Country, Tsinghua University and Beijing Institute of Technology! They are both cradles of Dragon Country's talent."

"So, everyone, I sincerely ask you, how do you calculate the exact height from here to the water surface?"

"Ah...this..."

No one expected that this Sakura man Watanabe actually came to seek help.

But calculating the height?

Everyone at the scene looked puzzled.

Wang Luxiang spoke first, and said with a wry smile: "I'm sorry, Mr. Watanabe, we can't calculate the exact height either."

"I have considered using the free-fall formula to calculate the height, but I have no idea of ​​the air resistance coefficient and the windward resistance area here."

"In the end, I could only try to substitute the conventional coefficients, and the results I got were not much different from my estimates."

"So, I finally chose to estimate. After all, without tools, I don't think anyone can control the height error within 3 meters..."

"Ah...is that so?"

After hearing this, Watanabe Ryuichi showed disappointment on his face.

To borrow a phrase from Long Guo.

Missing an inch is a thousand miles wrong.

The error of 3 meters is simply terrifying.

Because this determines the length of the elastic rope you choose, which determines your life or death.

If the elastic cord is even 10 centimeters shorter, the mechanical button will not be reachable.

If it were even 10 centimeters longer, its entire head might fall into the water and become a delicious meal for the crocodiles.

He looked at the crowd again.

"Gentlemen, do you have any other solutions? Please share them with us so that we can work together to overcome this difficulty."

Everyone was more or less the same, shaking their heads slightly.

Yes!

There are many ways to calculate the height of an object.

For example, you can use a barometer to observe the changes in air pressure caused by altitude, or use the free fall formula, a laser rangefinder, or even the simplest steel tape measure.

But the organizers didn't provide any tools at all, so everyone could only rely on estimates.

Since it is an estimate, the error is of course quite large.

But even so, no one was willing to tell their estimated height.

Because once your reasoning is refuted or questioned, you will no longer be able to stick to it.

When it comes time to calculate the length of the elastic rope, will you trust yourself or others?

Should I put my precious life into the hands of others?

This is about the determination to survive of all the challengers present, as well as their consistent self-confidence.

Don’t underestimate this simple bungee jumping challenge.

There is so much physics knowledge involved in it.

Gravity, gravitational acceleration, tension, elasticity, wind resistance, ductility, drop...

Etc., etc!

Everyone was silent for a while, then looked at the water and the crocodiles that were still swimming, and resumed their calculations.

Time is running out!

At this moment, there should be less than two minutes before everyone enters the cabin.

Once time is wasted and an accurate result cannot be calculated, death is imminent.

"Calculate the altitude?"

Unexpectedly, the panicked Song Xiaocheng started yelling again.

"Hey, Watanabe! Why didn't you ask them for help earlier? Why didn't you just ask me?"

“…Ask you?”

Watanabe turned around in surprise.

Not only him, but also Wang Luxiang and Su Ming who had just resumed their calculations were interrupted again.

The two were speechless.

No, bro!

Can I ask you, could you just be quiet for a moment?

Watanabe did not question Song Xiaocheng's intention, but showed joy on his face.

"Friend, do you know how to calculate the exact height? Please teach me."

As he said this, he even bowed deeply to the other party.

Song Xiaocheng was flattered, but he also knew that there was no time to waste.

He said hurriedly.

"Haha, Brother Long, my great grandfather once taught me a method of measuring distance in the wild. It can effectively measure distances within one thousand meters with the naked eye, and the error will not exceed one meter. The closer the distance, the smaller the error. How about it? Do you want to learn it?"

"Measure distance with naked eyes?"

Watanabe Ryuichi's expression became more respectful and he bowed deeply again.

"May I ask what your great grandfather did for a living? Please teach me."

Song Xiaocheng smiled and waved his hands: "He, haha, used to be an artilleryman, and killed countless Japanese soldiers. I guarantee that every shot he fired will hit the target."

Watanabe Ryuichi: ...

I'm also a bad-mouthed person.

He forced a wry smile and said, "Please tell me more. Time is running out."

Song Xiaocheng also realized that he had spoken out of turn and quickly spoke up.

When he opened his mouth, not only Watanabe Ryuichi, but many challengers also pricked up their ears.

Including Chen Ziqi, Wang Luxiang and others.

After all, measuring distance with the naked eye sounds novel, but can the error really be reduced to less than 1 meter?

To know.

If the error can be controlled, it will undoubtedly greatly increase one's chance of survival.

Song Xiaocheng continued.

"The principle of this thing is very simple. Most soldiers are required to master it, but my great-grandfather's method may be more accurate."

As he spoke, Song Xiaocheng stretched out his right thumb towards the water and closed his left eye.

"Let's use our right eye to look at my thumb, and use it to find a reference point on the water surface, um... let's take the motionless crocodile as an example."

"After you have positioned it, close your right eye and use your left eye to see..."

"At this time, I need to determine whether the reference object is offset. I need to estimate the distance of the offset. Then, based on the length of my arm and the distance between my two eyes, I need to multiply it by 10 to get our height above the water surface!"

"This……"

As Song Xiaocheng explained, Watanabe Ryuichi's eyes lit up.

"Trigonometric distance measurement! One of the commonly used methods in astrophysics to measure the distance to planets. Oh my God! Why didn't I think of it... Why didn't I think of it..."

Watanabe Ryuichi quickly followed suit and started testing according to Song Xiaocheng's method.

After estimating the offset distance, substitute the arm length and the distance between the two eyes, and the final result will be easy to calculate.

"103.5 meters! As expected, it is about three meters different from my estimate. Is this the exact value of the water surface height?"

Watanabe Ryuichi shouted excitedly.

When he shouted this, everyone present also heard this number.

103.5 meters?

Everyone silently compared the numbers in their minds with their own estimates, and some even stretched out their arms to try to use this method.

"Okay! Brother Xiaocheng! I think your method is more reliable."

Wang Luxiang finally regained his cheerful expression and put down the arm he had just stretched out.

"There is definitely an error, but it is much better than our method. At least it has shortened the distance by about two meters."

"Yeah, that's right, why didn't I think of this method."

Su Ming also put down his arms and sighed.

This distance measurement method is also called the eye-saccade method.

In fact, it is not uncommon, and many professional soldiers need to master it.

But a group of physics students at the scene actually forgot these common sense things.

If Song Xiaocheng hadn't reminded us, a large number of people might have died in this challenge.

Unconsciously, Su Ming's prejudice against him was reduced a little.

Seeing so many people starting to imitate his method, Song Xiaocheng put his hands on his hips and laughed.

"How about it, brothers? My mother isn't completely useless, right?"

Unexpectedly.

The voice just fell.

Song Xiaoxuan, who had been silent all this time, suddenly spoke.

"No! Brother, this method can only be used for horizontal distance measurement. When measuring vertically, the error will be even greater."

"Also, the distance from here to the water surface is not 103.5 meters, but 104.7 meters!"

boom!

When Song Xiaoxuan said this, everyone in the room was shocked.