Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mechanics, help me

  1. Apr 18, 2004 #1
    a weight is attatched midway to a thread which hangs vertically from a ceiling.another weight is attatched to the bottom end of the thread.where along the thread will it be most easy to cut and why?
  2. jcsd
  3. Apr 18, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    What's your initial guess (and why)?
  4. Apr 18, 2004 #3
    I would say at the top, near the point the thread is attached to the ceiling. Why?, because at that point there is the greatest amount of tension on the thread, which makes it easier to cut.
    My thoughts anyway.
  5. Apr 18, 2004 #4
    I would say that your initial guess is correct, because any part of the thread below the first weight does not experience tension from that weight.

    This is assuming it is easier to cut if it is more tense, which I think is a fair assumption.
  6. Apr 18, 2004 #5
    I would say anywhere between the ceiling and the first weight.
    regarding the assumption of higher tension = easier to cut, I would agree; it would flex less as the cutting object pressed against it
  7. Apr 19, 2004 #6
    The top of the thread due to it having the highest normal strain (change in shape and volume), the thread would elongate and become thinner allowing less work to be done to cut the thread.
    Last edited: Apr 19, 2004
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook