Một vật ném được thẳng đứng xuống đất từ độ cao 5 m. Khi chạm đất vật nảy trở lên với độ cao 7 m. Bỏ qua mất mát năng lượng khi va chạm đất và sức cản môi trường. Lấy g = 10 m/s². Vận tốc ném ban đầu có giá trị bằng
   

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Một số câu hỏi khác có thể bạn quan tâm.

• Find a mistake in the four underlined parts of the sentence and correct it:

  There are many competitions which having positive effects on competitors.

• Find a mistake in the four underlined parts of the sentence and correct it:

  I am looking forward to see the final of the elocution contest which will be organized at the auditorium.

• Find a mistake in the four underlined parts of the sentence and correct it:

  Population density is the highest in the Red River Delta, 1,136 people per km², and the

  lower in the northwest with only 62 people per km².

• Find a mistake in the four underlined parts of the sentence and correct it:

  Agricultural land per each capita decreased from 0.25 hectares in 1943 to 0.10 ha in 1995.

• Find a mistake in the four underlined parts of the sentence and correct it:

  Rapid population growth, migration, and urbanize in Vietnam have placed new pressure on

  the environment, particularly as a result of forest exploitation, and depletion of water

  resources.

• Choose the word that has the underlined part pronounced differently from the rest:

  teacher                   beat                   breakfast                     eating

• Choose the word that has the underlined part pronounced differently from the rest:

  passenger                  several                  begin                    repair

• Choose the word that has the underlined part pronounced differently from the rest:

  meeting                      weekly                    engineer                       free

• Choose a word that has different stress pattern:

  alternative                  announce                  absolute                    arrive

• Choose a word that has different stress pattern:

  typical                   continue                   tobacco                   appointment