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twichk12345
2 năm trước
Một con lắc đơn có chiều dài 1 m . Kéo cho nó hợp vs phương thẳng đứng 1 góc 45 độ rồi thả nhẹ . Tính lực căng dây treo của con lắc khi nó đi qua vị trí hợp vs thẳng đứng 1 góc 30 độ . Lấy g = 10m/s2 ( Áp dụng các định luật bảo toàn )
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Các câu hỏi liên quan

V. Complete the sentences with the correct tense of the verbs play, do or go. 1. Sarah__________gymnastics on Saturday evenings. 2. Mark__________badminton with his friends at the moment. 3. My friends and I__________climbing yesterday. 4. you__________table tennis last Sunday? 5. Jim__________basketball because he wasn’t tall enough. 6. We__________sports together when we were kids. 7. People often__________jogging in the park. 8. I__________judo now and I love it! VI. Complete the sentences with the correct form of the word in brackets. 1. He gets a lot of__________from football (enjoy) 2. Playing sports is a fantastic way to improve your __________. (fit) 3. My brother is not very__________. He doesn’t like playing or watching sports (sport) 4. Nearly half of the people in the world are__________in football (interest) 5. Pelé is__________regarded as the best football player of all tim, (wide) 6. Cristiano Ronaldo is a Portuguese professional__________. (football) 7. Pelé is a__________hero in Brazil (nation) 8. Winning three gold medals is great__________. (achieve) VII. Circle and correct the mistakes in these sentences. 1. The children feeled excited before their holiday. __________________________ 2. Do you play yoga at home or in a club? __________________________ 3. Where was you last weekend? -I was at home. __________________________ 4. The car stoped at the traffic lights. __________________________ 5. Paul is very tired because he didn’t slept well last night. __________________________ 6. Do you take part in the marathon last Sunday? __________________________ 7. Go straight ahead and then to take the first turning. __________________________ 8. When did you buy this house? - We buy it three years ago. __________________________ VIII. Match the questions to the answers. 1. Do you like to watch sports on TV? 2. What sports are you best at? 3. How much exercise do you get each week? 4. Did you do any exercise or play any sportsyesterday? 5. Do you prefer team sports or individualsports? 6. What is the most popular sport in the world? 7. Which is better, basketball or volleyball? 8. Why should people exercise? a. Volleyball, I think. b. Three or four times. c. Because it can help them be healthy. d. Yes, I like watching sports more than playing them. e. I don’t like either of them. I’m not a sporty person. f. Football or soccer. g. Swimming and Taekwondo. h. Yes, I played tennis with friends.

ai giúp mình với Chuyển các câu phủ định sau sang câu bị động. 1. I don’t know her telephone number. 2. They can’t make tea with cold water. 3. You mustn’t use this machine after 5:30 p.m. 4. I won’t hang these old pictures in the living room. 5. The German didn’t build this factory during the Second World War. 6. She didn't make the moon cakes last week. 7. He doesn't meet them in her school everyday. 8. Anna won't wtite a letter. 9. The workers haven't decorated their building yet. 10. The police hasn't arrested a burglar. 11. Two people aren't cooking dinner on the beach. 12. Tina isn't doing grammar exercises. 13. At this time last year, they weren't building this house. 14. I wasn't chatting with my friends while my teacher was teaching the lesson yesterday. 15. After the children hadn't finished their homework, they went to bed. 16. When she hadn't done her work she went to the cinema. 17. I am not going to watch films with my friend because I am sick. 18. My sister isn't going to cook a delicious meal for dinner.

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