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

Homework Help: Tension in a rope

  1. Aug 19, 2011 #1
    1. The problem statement, all variables and given/known data
    How do i find the tension in a cord. If two equal forces,say F1 and F2, act on both ends of the cord the tension is F1=F2. What if the forces are not equal?
    If a force A pulls one end of a rope, and a force B, pulls the other end and A is not equal to B, what is the tension in the rope.

    2. Relevant equations


    3. The attempt at a solution
  2. jcsd
  3. Aug 19, 2011 #2


    User Avatar
    Homework Helper

    If the rope has no mass, the forces at both ends are the same according to Newton's Third Law.
    The forces can be different at the ends if the rope has mass and accelerates, or is subjected to gravity. In this case, the tension is different at different cross-sections inside the rope.

  4. Aug 20, 2011 #3
  5. Aug 20, 2011 #4
    Technically, saying "the forces are equal" means they have equal magnitude and direction. Yes, the vast majority of readers will know what you mean but I've found its important to be somewhat pedantic in quiz questions. Otherwise a student can, for example, make the point I make here about the force, and its a valid point.
    Last edited: Aug 20, 2011
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook