"There is one to say one, there are two to say two, there are three to say three, Yang Shenshu has something in the teacher's house. "Family dinner in the evening," says Ranger.

"Applejack, you got the second in your grade, and you did your best. Lan Jinhui said a fair word, and he said: "Starting from May 1, your salary will increase by 130 yuan." ”

"Uh-huh......" Lan Jie was silent, noncommittal.

The rule set by Mr. Lan is that Lan Jie will increase his salary by 10 yuan in advance.

Lanjie improved from thirteenth to second place, and the correct value for the salary increase was 110 yuan.

Such a simple math problem, Mr. Lan will miscalculate?

Well, Mr. Lan drank a pound of sauce-flavored liquor, although it was not up to Mr. Lan's amount, a pound of liquor also produced more or less alcoholic strength.

But if Teacher Fan Lan eats two peanuts, he will not miscalculate the math problem. That's all Ranger can understand.

Lan Jinhui knocked two peanuts, and he said, "Ajie, you have a birthday in July, and I will give you an extra 20 yuan, and you will buy a few gifts you like on your birthday." ”

That's right, it is impossible for Mr. Lan, who moistens his throat with a pound of white wine, to miscalculate the math problem. Lan Jie expressed his gratitude: "Oh, thank you, Dad. ”

"Not in a good mood?"

"Thank you, Dad!!"

Lan Jie, who has received a bonus and a salary increase, has a firmer belief, learning is above all else, loving learning does not necessarily mean getting rich, and not loving learning will necessarily be poor.

Early the next morning, Lan Jie came to the classroom early, and the person who was earlier than him was Li Zihan.

"Morning, Zihan. ”

Lan Jie greeted Li Zihan warmly, Zihan was the second in the class (+3) and the twentieth in the whole grade (+33) this time, Zihan has made great progress, and Zihan, who is mediocre but extremely hardworking, is a representative of inspirational students.

Li Zihan responded: "Morning, Lan Jie. ”

"Brother Hanzi is in a good mood. Lan Jie was so moved, Li Zihan actually greeted "Morning, Lan Jie" for the first time.

Li Zihan took out his mobile phone, and he said, "You can get a WeChat QR code to take a look." ”

"Hmm!" Lan Jie was even more moved, Zihan was going to be friends with me.

The two added friends to each other, and their friendship was further sublimated.

After more than three semesters of hard work, Lan Jie finally became a friend to every student in the class.

Become your WeChat friend, and you can see your circle of friends.

Lan Jie entered Li Zihan's circle of friends with great interest, and Zihan only showed the updates within three days.

Li Zihan has not updated anything in the past three days, and his circle of friends is empty, with only a ruthless dividing line.

At the same time, Li Zihan was also checking Lan Jie's circle of friends, he turned around and asked, "On the 30th, you are going to the sports city to participate in the long jump competition?"

"Yes, yes. ”

"Are you sure you'll get a good place?"

"Yes, yes, yes. ”

"Lan Jie, in fact, I have nothing to do on the 30th, I may go to the sports city to watch the game, do you book the tickets in advance, or go to the site to buy?"

"Admission is free with a student ID. Lan Jiexian's surprise, he said: "The long jump competition is very boring, Zihan, will you really go to see me in the long jump?"

"This athletics event isn't just about the long jump, right?"

"Run, jumper, everything. ”

"Since it's free, you can enter the venue at any time, and we'll talk about it later. ”

"Okay, welcome Director Li to the site to guide the work. ”

His academic performance has improved, and his popularity has inexplicably improved.

Lan Jie's popularity was already Ness, and after he was promoted to the second strongest man in his grade, his popularity seemed to have become even more Ness.

The first class of Class 2 and 3 was a physics experiment class, and the students moved to the laboratory building to do experiments.

Although the class time of the experimental class is far less than that of the theoretical class, Tang Xiaoyun attaches great importance to the experimental class.

Before doing the experiment, Tang Xiaoyun said first: "If anyone fails to complete the experiment as required, then keep doing it until it is qualified." ”

In this experimental class, each student operates individually.

The experimental materials for each student were: two reading glasses, one thin converging lens, one pair of scissors, one screwdriver, one ruler, some cardboard shells, some translucent paper, and a few coloring pens.

Tang Xiaoyun's request was to use these materials to assemble a simple Kepler telescope. It is known that the minimum resolution angle of the human eye is 3×10^-4rad, and the diameter and focal length of the thin converging lens are both 2cm. The length of the lens barrel is required to be 62cm, and after the telescope is assembled, it can distinguish two engraved lines at an interval of 1 mm on the object surface at a distance of 100 meters.

The experimental requirements were clearly arranged, and the students immediately took action.

This optical experiment was relatively simple for Langer, who first had to calculate the diameter of the objective lens that met the conditions before assembling the telescope.

The eyepiece is a small, delicate thin converging lens, with a diameter and focal length of 2 cm, which is a known condition.

The objective lens is reading glasses, and there are two reading glasses, one large and one small.

The diameter and focal length of these two reading glasses can be measured with a ruler, and what Lanjie has to do is to choose the right reading glasses.

Due to the diffraction effect of the objective, the minimum resolution angle δθt that a telescope can resolve is determined by the size of the objective, i.e., δθt = 1.22λ/D.

In the formula, D is the diameter of the objective lens, λ=550nm is the most sensitive yellow-green wavelength for the human eye, and the minimum resolution angle is δθm1mm/100m=1×10^-5rad, so δθt≤δθm, D=6.7cm is obtained.

Ranger quickly calculated 6.7cm in his sketchbook, so he opted for reading glasses with a diameter of 6.7cm.

"The first hurdle to pass in this experiment is theoretical calculations, first calculate the correct objective diameter, and then choose the right objective. Although the theoretical calculation part of this experiment is not difficult, this type of optical experiment is ever-changing, and the difficulty of the experiment changes as the known conditions change. Tang Xiaoyun walked back and forth, and she gave some hints while supervising the work.

Lanjie uses a screwdriver to remove the lenses of reading glasses, and the lenses are smoothly separated from the frame.

Some students have extremely strong hands-on skills, and some students have extremely poor hands-on skills.

The routine operation of removing the lenses is not difficult at all, but some students are in a hurry and cannot remove the lenses.

"Huang Yuhang, stop me!" Tang Xiaoyun snorted, her face gloomy.

Huang Yuhang is very thoughtful, he doesn't need a screwdriver at all, he dismantles the lens with his bare hands, click!

The bird is big and there are all kinds of forests, Tang Xiaoyun stomped her feet irritably: "Huang Yuhang, did you dismantle the lenses like this? Deliberately destroy the experimental props, 0 points! Not only 0 points, but also lose money!"

Huang Yuhang is also very innocent: "Teacher Tang, the screwdriver doesn't work......"

Tang Xiaoyun angrily reprimanded: "Nonsense! Other classmates dismantled it well with a screwdriver, but it won't work for you? You disassemble it for me and use a screwdriver!"

Tang Xiaoyun stared at Huang Yuhang alone one-on-one, she was both angry and self-reproachful and said: "Huang Yuhang, your hands-on ability is so poor, did I not teach it well, or were you born with a handicap?"

"Teacher Tang, you taught very well, it was my deep hand handicap, which lowered the average of our class......" Huang Yuhang apologized again and again, he used the right tools under the guidance of Teacher Tang, and finally removed the lenses of reading glasses through the right methods.