dưới tác dụng của lực kéo 150N, một vật khối lượng 25kg chuyển động nhanh dần đều từ trạng thái nghỉ, sau khi trượt được một đoạn đường dài 6m, tốc độ của vật bằng 8m/s. a/Tính độ biến thiên động năng của vật? b/công của lực ma sát? Từ đó suy ra độ lớn lực ma sát?

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II. Word form: 1. The____________fish are floating in the water. DIE 2. Do you know what_____________cause air pollution? POLLUTE 3. The river is________by the dumping from nearby factories. CONTAMINATE 4. Noise pollution can also lead to headaches and high blood_________.PRESS III. Rewrite sentences by combining two sentences into one sentence and using suggested clues: 1. The air is so dirty. I sneeze so much. CONDITIONAL SENTENCE TYPE 2 ______________________________________________________________________ 2. Their children have birth defects. The parents were exposed to radiation.BECAUSE _____________________________________________________________________ 3. The air pollution causes breathing problems. LEADS _____________________________________________________________________ V. Write the correct form of the verb in the brackets to complete the following sentences 1. We all adored (1.do)_____ aerobics when we were young. 2. 30 years ago, we (2.not have)________ mobile phone. 3. The girl (3.cry)_____ when a fairy (4.appear)______. VI. Rewrite or combine the sentences, using the suggested words. 1.Vinh really loves to hang out with his friends. => Vinh really enjoys……………………………………………………………… 2. Playing beach games is very interesting. => It is…………………………………………………………………………… 3. The girl worked hard. Her step mother wasn’t happy ( Although) =>…………………………………………………………......................................