question_answer 66)

                  A mass of 2kg is suspended with thread AB (Fig.). Thread CD of the same type is attached to the other end of 2 kg mass. Lower thread is pulled gradually, harder and harder in the downward director so as to apply force on AB. Which of the threads will break and why?

Answer:

                  Force acting on the thread AB = mg + applied force. Force acting on the thread CD = applied force. Since, force acting on the thread AB is greater than die force acting on the thread CD, so thread AB will break.