Xueba God-level system

"Ding Lingling..." The melodious and urgent sound of the alarm clock rang.

Niu Zihao turned off the noisy alarm clock and went back to sleep.

"Sleep for another minute, then get up!"

This 1 minute is so short and so long.When he woke up, it was already three hours later.

"Oops, I overslept." Niu Zihao began to complain, "It must be because I read comics for too long last night, so I couldn't get up in the morning. I had no choice but to go to school and get approval from the teacher."

He hurriedly got out of bed, brushed his teeth, washed his face, and headed straight for the school.

In the classroom, Yang Junsheng, a physics teacher, slapped the podium and cursed angrily: "Look at your monthly exam results, there are 71 students in the class, and 60 talents with a score of 8 or above. As your substitute teacher, I have all I feel ashamed to meet someone soon.”

"And..." Obviously, Mr. Yang strengthened his tone, "I don't know how to take the test. Some students actually scored 13 points in the physics test. For a 100-point question, only 13 points were tested, and the multiple-choice questions were correct. Although I wrote a few fill-in-the-blank questions, they were copied from the options in the previous multiple-choice questions. Write a formula, and the grading teacher will be merciful and give you a score of 1 or 2. Niu Zihao, the physics score is 13, which one, stand up and let everyone know."

After speaking, there was silence in the classroom.

After a while, no one stood up.

The classmates started to talk a lot. It could not be that the teacher got the wrong test paper. It may be the ordinary class, like the students in our key class.

This Niu Zihao is going to be unlucky. With a score of 13, I closed my eyes and answered the test paper, which is also higher than this score.

……

Rushing rustling, classmates, you are talking non-stop, but no one is willing to stand up.Besides, it's not long since school started, and there are so many people in the class, who knows what Niu Zihao looks like?

Teacher Yang also smiled a little embarrassedly at this time. Sure enough, Jiang was still old and hot. That kind of smile is similar to a skin smile but a fleshy smile, and ordinary people can't detect it.As a teacher Yang who has been in vocational education for more than ten years, what kind of dilemma has he never encountered!

"The last vacant seat in the middle, is it Niu Zihao?" Teacher Yang asked, looking at the vacant seat.

"Yes, he may have asked for leave today." Zhao Liyang, who was at the same table, stood up and replied.

"If you ask for leave, then you can do the questions on the blackboard. It's a bit similar to question 5 of this monthly exam paper, but it's a little bit more difficult."

The hearts of the classmates at the bottom were pounding, but they lowered their heads and stared at the monthly exam paper in their hands.

As a student, who is not afraid of the teacher's classroom questions?Of course, there is one exception - the scholar.

Some students have already taken out paper and pen, staring at the questions written by the teacher on the blackboard, and quickly looking for formulas that can be applied in their brains.Like this type of question, as long as you can solve one, the other ten or twenty questions will be easy to solve.Some students couldn't even remember the formula, so they took out the handheld treasures bought in the bookstore and started to read.Handheld Treasure is actually a record of some required knowledge points in the book. Because of its small size, it can be read at any time, and it can also be carried with you. It is convenient and fast, and is deeply loved by the majority of middle school students.

Seeing Zhao Liyang stepping onto the podium, the classmates held their breaths. Can this little girl solve this problem?

"Don't look at me, I don't know how to do it!" The classmates at the bottom whispered, turning the pen in their hands for a while, looking at the watch for a while, and finally locked their eyes on Zhao Liyang on the podium.

In the quiet classroom, the air seemed to have frozen at this time, and only Zhao Liyang's figure when solving the problem became the focus of the audience.

A boy with glasses sitting by the window, the boss with his mouth open, can put an egg in it.The sun shone on his warm face, and he didn't waver at all when he watched her solve the problem.In his heart, perhaps it is no longer a wave of waves, but a stormy sea.Beautiful, that girl looks like my love when she solves the problem.Watching her solve the problem, there is quite a kind of taste of "the scorpion is green, the white dew is frost; the so-called Iraqi people are on the side of the water".

What no one will know is that the boy has secretly made an oath, if Zhao Liyang solves this problem correctly, then she will be the goddess in my mind in the future.

All the classmates, including Zhao Liyang herself, hope to solve this problem to prove that the key class is not a vain name.

Zhao Liyang looked up at the blackboard and saw:

A car moves along a straight road with a uniform acceleration of 2s2, then at any 1s( )

a. The speed is increased by 2 times

b. Speed ​​increased by 2s

c. The displacement increases by 2br />

d. Acceleration increases by 2s2

Although the title is very simple, with only a few words, it involves common physical quantities related to acceleration, velocity and displacement. If you don't know how to use the formulas reasonably, you may make mistakes.

The students below were just staring at the blackboard, no one wrote, but a few turned the pages.

"Three long and one short, choose the shortest, and three shorts and one long, choose the longest. This answer is not too long. I think if you choose c, who can make it the shortest!" A student began to use his own problem-solving strategy.

"Nonsense, the choice of c is pure foolishness, I think it is d. There is a 2s2 in the question, and there is also a 2s2 in the answer. Listen to me, the choice of d is correct."

Those who choose a, those who choose b, in short, there are people who choose the four options, just as, there will be a thousand Hamlets for a thousand readers.

Zhao Liyang took a serious look at the question. First of all, the answer d can be completely ruled out, and the key to doing uniform acceleration movement is the word "uniform". 2s2, error.

Acceleration is equal to the velocity change in unit time, which is combined with the definitional analysis and judgment of acceleration.

The displacement increment in any 2s is analyzed according to △x=at1.

Answer c: According to △x=at2, the displacement increases by 1 in any 2s, so c is correct.

In the same way, the answer b can be obtained: according to the definition of acceleration a=△v/△t, there is △v=a△t, so △v=1x2s=1s in any 2s, that is, the speed increases by 1s in any 2s, so a is wrong , b is correct.

Looking at Zhao Liyang's problem-solving ideas written on the blackboard, Teacher Yang, who had been watching next to him, glanced at him unconsciously.This... is exactly the same as the correct answer, and even the solution to the problem is the same.

Looking at the students I teach, can have such a thinking, I am also very proud of being a teacher. "Okay, you go down."

The teacher's face also changed from cloudy to cloudy just now, to cloudy and eye-catching in an instant.

At this time, the voice shouting "report" came from the door.

"Niu Zihao, come in!"

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