Một thước AB có thể chuyển động quanh một trục nằm ngang O, như hình vẽ. Biết OA = .   Gọi P1 là trọng lượng treo ở và P2 là trọng lượng treo ở . Muốn cho thước cân bằng thì:

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Choose the best answer for the following sentence:

  He asked me if I had seen his wife _____________ .
  
  

• Choose the best answer for the following sentence:

  _____________ couldn’t understand what she was saying.
  
  

• Choose the best answer for the following sentence:

  Tell me if you see ___________ unusually.
  
  

• Choose the best answer for the following sentence:

  ___________ is ready for the party.

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

  I asked the salesman if I could change the faulty camera with another one.

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

  Let’s go to the airport now just in case her plane will arrive early.

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

  The library is divided in two sections.

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

  She apologized and said that she won’t do it again.

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

  She said the doctor that she was unable to sleep.

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

  loud                           sound                         scout                       bought