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uyendinh10
2 năm trước
Một vật có khối lượng 1kg Được thả rơi từ độ cao 20m. Bỏ qua lực cản không khí lấy g= 10m/s² a) Tính thế năng của vật khi thả và suy ra cơ năng của vật b). Tính thế năng của vật ở độ cao 10m Suy ra động năng của vật tại đây c) Tính động năng của vật khi chạm đất Suy ra vẫn tốc của vật khi chạm đất
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bài này khó quá bạn nào giup mik với X. Read the passage and choose the best answers to the questions below: My name is John, and this is my story. Last year just before Christmas my family and our cousin and uncle and aunt decided to go to Perth for holiday. We went in two cars but when we were about halfway there my uncle wanted to turn round and come back. He said it was too far, and it was terribly hot too, one day it was 48 0 C. Even at night it was really hot. Anyway, what we decided to do was to drive back about 160 km to a place where the train went through. Then we put both cars on the train and we all went to Perth by train. That was fun. It was a good train. We had a good time in Perth but we had to cut our holiday short. You see, while we were there, my grandmother in Melbourne died. Most of us flew back but my Dad and my uncle came on the train with the cars and then had to drive back to Melbourne from Port Pirie. It was a really strange holiday because nothing went the way we planned it. 1. When did John’s family go to Perth? A. before Christmas B. before Easter C. before Thanksgiving D. before the New Year 2. Why did John’s uncle want to come back? A. Because it was too hot. B. Because he was too cold. C. Because he was too tired. D. Because it was too boring. 3. In the end John’s family went to Perth……………………. A. by train B. by coach C. by car D. by plane 4. Who died when John’s family were on holiday? A. his mother’s father B. his mother’s mother C. his father’s mother D. his father’s father 5. Most of John family came back…………………… A. by train B. by ship C. by plane D. by car 6. Who in John’s family had to go by train and car to Melbourne? A. his father B. his uncle C. his parents D. his father and uncle

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