Câu 9: Ô tô đứng yên khối lượng 2 tấn bắt đầu chuyển động với gia tốc a=2m/s2 trong vòng 10 s. Cho hệ ma sát bằng 0.1 và g=10m/s2. Tính công và công suất của động cơ ô tô?
Câu 10: Ô tô khối lượng 5 tấn đang chuyển động với khối lượng vận tốc 54km/h thì hãm phanh và dừng lại sau 10 s . Tính lực cản và công của lực cản trong trường hợp này?
Câu 11: Một ô tô có khối lượng hai tấn đang chuyển động thẳng đều với vận tốc 36km/h trên một đương thẳng nằm ngang, biết quãng đường AB dài 450m và vận tốc của ô tô khi đến B là 54km/h. Cho hệ số ma sát giữa bánh xe và mặt đương là 0.4, g=10m/s2. Tìm:
a.độ lớn của lực phát động
b. công của lực phát động thực hiện trong khoảng thời gian 30 phút
c. công suất của động cơ
Câu 12: Một ô tô có khối lượng 2 tấn khởi hành từ A chuyển động nhanh dần đều về B trên một đường thẳng nằm ngang, biết AB = 450m và vận tốc của ô tô khi đến B là 54km/h. Cho hệ số ma sát giữa bánh xe và mặt đường là 0.4, g=10m/s2. Tìm:
a. Công và công suất của động cơ trong khoảng thời gian đó
b. Động lượng của xe tại B
c. Độ biến thiên động lượng của ô tô, từ đó suy ra thời gian ô tô chuyển động từ A đến B

Exercise 3: Find the word whose meaning is of the similar meaning with the underlined word of each sentence

1. In some rural areas, students don’t have many chances to get access to the Internet.

A. time B. opportunities C. performances D. rights

2. We should get rid of gender and race discrimination in community.

A. encourage B. reduce C. enrol D. eliminate

3. Women represent 40 percent of the country’s workforce.

A. Females B. Males C. Children D. Adults

4. Women should receive the same rights as men.

A. unequal B. equal C. different D. exact

5. Some people think that women should stay at home and do household chores.

A. say B. allow C. suppose D. want

6. There were no limitations on women’s service at FDNY. Everyone had to do exactly the same jobs.

A. restricts B. interests C. subjects D. inequalities

1. They ......................... Ho Chi Minh City last summer.

2. He asked me if I ......................... to school by bicycle every day.

3. ......................... Friday morning, there is a meeting between 11 am and 1 pm.

4. The article was posted by Jimhello on Tuesday, .........................?

5. She was sick yesterday, ......................... she was absent from school.

6. I didn't go to the party yesterday because ......................... .

7. They are living in a house that ......................... in 1930.

8. I'm learning English ......................... I want to get a good job after school.

9. Why ......................... go to the park for a change?

10. My father ......................... for the car factory since 1995.

11. - The alarm's going. It's making an awful noise. - OK, ......................... it off.

A. I am switching B. I am going to switch C. I'll switch

12. - Did you buy this book? - No, Emma did. ......................... it on holiday.

A. She'll read B. She is going to read C. She reads

13. - Is the shop open yet? - No, but there's someone inside. I think ......................... .

A. it opens B. it's about to open C. it will open

14. - Have you heard anything about Jane? - Yes. She's engaged. .................... married in June.

A. She's getting B. She'll get C. She's about to get

15. - I'm just going out to get a paper. - What newspaper ......................... .

A. will you buy B. are you buying C. are you going to buy

16. I would like ......................... Holland.

17. Don't forget ......................... the door when you go out

18. He is not very good ......................... mathematics.

19. I suggest ..................... a short cut through the park. It'll take much less time.

20. I am always remember ......................... off the lights before I leave my house.

21. Did you remember ......................... Jack my message?

22. Don't forget ......................... your homework tonight!

23. It's important .........................

24. It's no good ......................... him the truth now.

25. He is very ......................... in my story.

1. When you do something good for others, you will find your life _______.

A. meaningless B. hopeless C. harmful D. meaningful

2. Internet helps us interact _______ people all around the world.

A. on B. in C. with D. of

3. We all feel _______ about going on tours around Hanoi.

A. interested B. excited B. bored D. tired

4. Doing volunteer work, we are more_____ of global problems facing our world.

A. aware B. devote C. communicate D. dedicate

5. I really wanted to take part in this contest, _______ my parents allowed me to.

A. and B. or C. so D. but

6. - “What do you think of this song?” - “It sounds _______. I don’t like it”

A. interested B. bored C. boring D. interesting

7. Yesterday I got to the station late, but _______, the train was late, too.

A. fortunately B. fortunate C. unfortunate D. unfortunately

8. That’s a very nice dress you’re wearing. - _____.

A. I’m glad you like it B. That’s all right C. That’s nice D. You’re quite right

9. ______ is the member of a family who earns the money that the family needs.

A. Husband B. Breadwinner C. Women D. Homemaker

10. This system of the body lets us breathe in oxygen with our ___ and breathe out carbon dioxide.

A. heart B. lungs C. brain D. intestine

11. This system of the body is _______ up of our bones.

A. made B. taken C. done D. got

12. Last night my favorite program________________ by a special news bulletin.

A. interrupted B. was interrupted C. were interrupted D. is interrupted

13. _____ is the controller of the body. Led by the brain and nerves, it allows us to move, talk and feel emotions.

A. Circulatory system B. Digestive system C. Nervous system D. Skeletal system

14. I often ______ at the market near her house.

A. clean the house B. shop for grocery C. do the cooking D. feed the cat

15. “Suoi Mo”, the debut album by Trinh Cong Son, is sweet and gentle.

A. first B. second C. third D. new

16. A lot of fans gathered at their idol’s home to see her after the contest.

A. contestant B. competitors C. judges D. devotees

17. Her exceptional ability is known widely as she has won a lot of prizes in many different contests.

A. talent B. passion C. admiration D. appearance

18. Volunteer work is a great way to _______ experience in a broad range of fields.

A. take B. gain C. do D. make

19. Last year, my class _______ to teach the children in a remote area.

A. volunteer B. voluntary C. volunteered D. volunteers

20. Joe: "John says he doesn't like you". Sue: "………………………………"

A. I'm not mind at all B. It is the same C. I don't care D. So do I

21. The film was nominated ……………… an Academy Award.

A. for B. in C. about D. with

22. Most people believe that musicians are born with special talents.

A. natural ability B. mental capacity C. good taste D. wisdom

23. She made her professional stage ………………. in Swan Lake.

A. appearance B. debut C. view D. Both A and B

24. The region is renowned for its outstanding natural beauty.

A. known B. famous C. available D. recognized

25. It is considered to be a …………………. disc in this year.

A. platinum B. silver C. blonde D. famous

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