Tang Dou reluctantly went to the second bedroom and sat next to the girl and said, "Who can't do it?"

"This is the option C." Tang Tang pointed to the multiple-choice physics question with a pen, tilting his head, looking like he was desperate, and he was so sad in his heart, why should science have physics?

“c. The frictional force is backward when a person walks forward.”

Tang Dou read all the options, and the person moved forward and the friction backward. At first glance, nothing happened. If there wasn't a top student's brain now, Tang Dou would have been completely confused. He asked the girl: "How to determine the direction of friction?"

"Contrary to the direction of movement or the trend of movement." Tang Tang answered skillfully.

"So people move forward, so the friction is backward?" Tang Dou continued.

Tang Tang nodded.

That's how she understood it, she felt nothing wrong, and suspected that the answer was wrong.

"No matter what force you study, don't worry about the target as a particle at the beginning, as this will limit your thinking. The first step in the mechanics problem is to judge the type and direction of the force. You need to study the contact surface between the target and the reference object, and when you figure out the direction and calculate the size, then treat it as the force decomposition of the particle stroke."

Tang Dou returned to the option, "Walking, don't care about the direction of your body's progress. The friction of walking is definitely caused by the contact and squeeze of the soles of the feet and the ground, so you need to study the soles of the feet."

"Actually, normal people do not slide relative to the ground when walking, they jump up, jumping, so it is static friction. Can you think about this?" Tang Dou said with his palm sliding on the table.

Tang Tang nodded with her mouth open, and it turned out that she had made the friction type wrong. No wonder the more she was more confused.

"This is why you can't judge before. Static friction is a little more complicated than dynamic friction. It can stop supplying power. You can move forward because of this. There are also cars that are moving forward and are subject to both dynamic and static friction. Static friction provides power. Dynamic friction is resistance. You can experience it yourself later." Tang Dou raised his hand:

"Stand up and take two steps, slow down."

The old girl stood up obediently.

Walk towards the door, step by step.

"Don't look at your eyes, feel it with your brain." Tang Tang stepped out his left foot, and just raised his right heel, Tang Dou shouted: "Stop, feel the movement trend of your right foot."

"The soles of the feet are pushing back, so the static friction force is forward. It's so simple. I used to be the target to analyze the overall situation." Tang Tang suddenly realized that her mind was originally a scattered mud in her mind, but after being explained and demonstrated by her brother.

"I thought you were really lucky in the college entrance examination." Tang Tang said with a smile. My brother was so hiding that he couldn't reveal it, and the questions were very simple and vivid.

"If you don't have anything in your head, try 600 points." Tang Dou rolled his eyes, "The friction of the car is often tested. Can you judge clearly now?"

"Yes." Tang Tang nodded vigorously.

"Okay, how long has it been since the first year of high school started? I haven't learned much knowledge. I just need to figure out the friction today, let's play." Tang Dou advised his sister.

"I made the notes." Tang Tang opened the notebook and wrote quickly.

Shen Yun in the hall was unhappy again, so he didn't care about his brother who advised his sister not to learn from him.

"Doudou is right. Tang is only in his first year of high school now, so he will have fun when he is on vacation. He doesn't learn much every day. It's okay to figure out a knowledge point. Tang is very conscious. Don't force her all day long." Old Tang advised Shen Yun.

Of course, Shen Yun knew that working and rest were combined, so she asked her daughter to study in the morning.

"Brother, let's play Landlord." Tang Tang said after taking the notes.

"Wait a minute, are you playing Tiantian Cool Run?" Tang Dou Zheng finished his daily mission.

"Mom doesn't allow it. The family only allows me to play Landlords, but the school doesn't allow me to bring my smartphone." Tang Tang whispered, and said: "The school doesn't allow me to play with mobile phones. Teacher Mu has been promoted to director of academic affairs this year and has been stricter in charge."

"He has always been very strict with himself. In the past, he was only strict with his own class."

Of course, Mu Jinhua's strictness Tang Dou knew that Han Wentao was also a good student in front of him.

On October 1st, Tang Dou would rather stay at home to read books than go outside, but the old girl had a rare holiday, so she took her to the same city and made an appointment with Mu Wanying to go with her after lunch. The three of them went to the Furong Garden of the Tang Dynasty first.

Tang Dou and Mu Wanying have a student ID ticket for half the price, and Tang Tang uses an ID card for half the price for minors.

The Furong Garden in the Tang Dynasty is suitable for roaming, with pavilions, gardens, waterfalls, lakes and streams. You can bring some food and drinks. You can walk and sit in groups of three or five, and you can sit leisurely and relax.

In this golden October, the sky is high and the clouds are light, and the coolness in the wind eliminates the autumn tiger.

Tang Tang and Mu Wanying were talking and laughing in front, but there was basically nothing Tang Dou had to do. Tang Dou was leisurely playing with his mobile phone behind him. Some foreigners asked him to help take pictures in foreign languages. Tang Dou actually understood it and took the camera and took a few photos.

"thank    you    very    much." The foreigner thanked repeatedly.

"you’re   e, wish   you    a   good    trip." Tang Dou replied in a simple and smooth manner.

"Thank you, bye." The foreigner said goodbye in broken Chinese.

Mu Wanying and Tang Tang were surprised in front, and Mu Wanying said, "I didn't realize that Doudou's spoken language is so good."

"Isn't this the most daily communication? I have always been practical in my studies. If I can't test you in the exam, my speaking may not be worse than you." Tang Dou pretended to be a big match.

Mu Wanying was kind and was very upset. Her English was her best, but she was trampled by Tang Dou.

"Brother, you're almost OK. You can compare with Sister Wanying except Chinese." Tang Tang immediately poured a basin of cold water.

Tang Dou was ashamed of himself, and his Chinese language exam was better than Mu Wanying.

"What happened last night? I was scolded by your mother as soon as I got back." Mu Wanying asked Tang Dou.

"My mother thought I had let you down and insisted on severing the parent-child relationship with me." Tang Dou.

Mu Wanying was about to say the ghost letter, but she changed it to her mouth, "It's so exaggerated."

"My mother is so angry. I have saved up some anger for my brother for a few days." Tang Tang briefly talked about Mile's gift.

Mu Wanying looked at Tang Douyanran and smiled and said, "That 'rice' in your class. She wanted to give me one million last night and let me leave you. I think it's a good deal to get one million for nothing. I'm considering it."

"It seems that I am more valuable than you. Once in the second year of high school, Han Wentao gave me 500,000 yuan and asked me to leave you."

Tang Dou smiled indifferently.

Mu Wanying was a little unhappy. Han Wentao actually disgusted her so much behind her back. She is like Han Wentao's style of doing things like Han Wentao, who likes to use money to smash people. Mu Wanying asked:

"Then why don't you agree?"

"I think you still have room for appreciation. Before the age of 25, if you have good maintenance, you will steadily increase or decrease before the age of 30. It will be worth at least 2 million after graduation from college." Mu Wanying bit her lip and kicked Tang Dou, and Tang Dou said again:

"If I do, I can take action with one million. I won't have this store after passing through this village."

The classmates are called Tang Dou Han Dou, but in fact, a group of Tang Dou Jings.

To be honest, although Tang Dou and Mu Wanying were stumbling after marriage in their previous life, it cannot be denied that Mu Wanying was a good wife. It would be a blessing to marry him for 500,000 yuan. Of course, Tang Doubai married him, and Mu Wanying's parents also accompanied him in the suite.

"You are narcissistic, I haven't decided whether to buy you yet." Mu Wanying shook her head and turned around, so arrogant, and suddenly turned around and said, "How did you answer Han Wentao at the beginning?"

"I ask Han Wentao to carry a pack of money to you, maybe it will succeed." Tang Dou.

Mu Wanying smiled and said nothing, squatting by the pond to look at the carp in the water.

Brother and Sister Wanying are so handsome. Tang Tang feels like she has made a light bulb.

After visiting the Furong Garden of the Tang Dynasty, I went out to watch a movie, and after dinner, I went to the Big Wild Goose Pagoda. At around 6 o'clock in the evening, the Big Wild Goose Pagoda is really nice. The beautiful Tang suit and the Hanfu girl is so pleasing to the eye.

There will be a musical fountain later, and the fountain will bloom with the melody of I love you motherland, which is very exciting.

ps: Oli gives in the college entrance examination.
Chapter completed!