cho bộ truyền đọng đai sau ;bánh dẫn 1 có đường kính 20 cm , bánh bị dẫn 2 có dường kính là 10 cm A.tính tỉ số truyền i của bộ truyền động đai ? B hãy xác định tốc đọ quay của bánh bị dẫn 2 ,biết rằng bánh dẫn 1 quay với tốc độ 15 vòng /phút

giúp mình bài 2, bài 3 nha mk sắp thi rồi cảm ơnnn

Ai giúp mình với ạ, mọi người giải theo hướng tự luận ạ. Em hứa vote 5 sao

Ngâm thanh Fe có khối lượng 50 g vào 300ml dd Cu(NO3)2 0,1M. Sau 1 thời gian lấy thanh kim loại ra khỏi dung dịch thì thấy nồng độ của Cu(NO3)2 là 0,02M. Tính m thanh kim loại phản ứng

Chứng tỏ rằng : 3.5.7.9+9.13.15.17 chia hết cho 2 ---- ---- ab + ba chia hết cho 11; ----- ------ + ab - ba chia hết cho 9 (a>b) Giúp mik vs ngày mai mik kiểm tra rồi

Các anh chị giúp em với ạ ( Bài VI và VII ạ )

Mong mọi người giúp mình câu 1c

zn +hno3 => zn(no3)2 + no + no2 + h2o cân bằng bằng phuong pháp oxi hóa (trình bày)

II. Choose the correct answer. CORE 1. Tet is (a/@n/ the /0) occasion for family reunion in Viet Nam. 2. We broke with tradition (by/ of/about/ for) making fruit jams instead of cakes at Tet. 3. (What/Which/ Who/Where) ethnic group has a larger population, the Khmer or the Cham? 4. The Hung King Temple was a local festival; (nevertheless / therefore / but / moreover), it has become a public holiday in Viet Nam since 2007. 5. I (don't visit/ won’t visit / haven't visited/ am not visiting) my form teacher since I left school. 6. In Viet Nam, the cutlery we mostly use is ( knives/ forks / chopsticks /plates). 7. Some peoples in the mountains of North Viet Nam used to have a (nomadic / happy / interesting/ good ) life. They moved to get food and find new land for growing rice. 8. Farmers are busy collecting their crops at ( harvest time/ summer time / spare time/ freetime ). 9. A tent can be more easily(pulled down/put down/pulled up/ put up)and transported than a ger. 10. If you fancy (being/to be / to being/ be) outdoors, play some sports together. 11. My father used to fancy (go /goes/going/went) hunting in the forest. 12. The US is a (multi-cultural / bi-lingual / many-culture/ multi-country ) country with over 80 ethnic groups. 13. The Gong is a popular ( musical / music / musician/ musicology ) instrument of the ethnic minority groups in Central Highlands. 13. The Yao have (a/ an/thel some) rich culture of folk literature and art, with tales, songs, and poems. 14. The crops (depend heavy/depend heavily/affect heavy/affect heavily) on weather. 15. She is beautiful; ( therefore/ though/moreover/otherwise), she's very clever. 16.The Thai wish a happy and (healthy/ comfortable/ wealthy /lucky) life when they p the Xoe dance. 17. Most ethnic minority peoples are good ( at/ for/ to/ in) farming techniques. 18. In some areas, when you meet old people, you (should/ shouldn't/ don't have to/ has to take off your hat to greet them and show your respect. 19. ( Which do you think/ Which you think / What do you think/What you think) is the mos interesting museum in Ha Noi? - I think it's the Museum of Ethnology. 20. He has been living 15 km away from Nha Trang; (if/ moreover / however/ while), he has never been to Nha Trang Carnival. 21. A tourist travels (cheaply/ more cheaply/cheaplier/ cheaper) than a business person. 22. ( Good/ Vegetable/ Vegetarian / bad) meals are offered freely at Ba Den Temple. 23. People burn incense to show respect to their (grandparents /ancestors/ relatives/ neighbors) 24. The King was very happy ( because/ although/ while/so) Lang Lieu brought special cakes he had made. 25. She is beautiful; (therefore/ moreover/ otherwise/ however), she's very clever. 26. The festival is held every year to ( worship/ respect/ commemorate/ commemorates) Sain Giong. 27. The volunteers have to work much ( more hardly than / harder than / the hardest than harder) usual to save the dying animals from the forest fire. 28. When the moon appears, children raise their ( clean/ clasped/ two/ right) hands to the moo 29. According to the (tables ways / table manners / behaviours / differences) in England, have to use a knife and fork at dinner. 30. A tradition is something special that is (passed / passed to / passed down / passed through the generations. of verbs in brackets: III. Use the correct tense of verbs in brackets: 1. I was home late but my friends (wait)... 2. Tom (fall).... 3. We don't mind (train). 4. Kathy (be).. 5. You shouldn't 6. This is the first time we (see). 7. Our family (Ilive).... 8. This task must (complete). 9.The girl ( cry)... 10. While I (shop).. 11. Although it was noisy, I (keep).. 12. When she was crying, he (hug).. 13. I don't like to speak English because I (be).. 14. While I (do).... 15. My family (go). when I (arrive). off the ladder while he (paint)... .the ceiling. pets. .quite different since she got married. (break) your promise to the children. .the Statue of Liberty. happily in the country than in the town since last year. before 9 o'clock this Saturday morning. when a fairy appeared. I (meet). one of my old friends. .on studying. her. .afraid of making mistakes. my homework, the telephone rang. ... .to Nha Trang to join the Carnival next June. ..... IV. Do as directed: 1. It took her three hours to finish the composition. (Make question for underlined words) 2. Hung drives more carefully than his brother. (Rewrite, using "carefully") - Hung's brother 3. In the Central Highlands, the biggest and tallest house in the village is the communal house. (Make question for underlined words)

Câu 5c ạ xin mọi người giúp mình v