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Homework Help: Cable tension force from applied force

  1. Oct 8, 2012 #1
    Hi, Im a bit confused about cables, because of multiple people telling me different things. The only times weve discussed cables/springs is when a force is applied parallel to the length of the cable.

    So say you had a cable tied to 2 fixed ends ------------------ , (great diagram eh) and a force is applied upwards to the centre of the cable(it has some elasticity, as cables do). Is the tension in the cable = the force applied?

  2. jcsd
  3. Oct 8, 2012 #2


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    Hi J3Di! Welcome to PF! :smile:

    There are three forces acting on the centre of the cable: applied force upward, and two equal tension forces to left and right and slightly downward.

    The three forces have to add to a net force of zero. :wink:
  4. Oct 8, 2012 #3
    Thanks for the welcome, and the answer :smile:

    So suppose this cable breaks when it reaches a certain tension force. This tension force will be reached by applying force the centre of the cable like before. (I get that the vertical components of the tension forces would add to equal the applied force.)

    Would the cable break when each of the 2 tension vectors were equal to the given breaking point, or when their magnitudes totalled the given breaking point?
  5. Oct 9, 2012 #4


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    each :smile:

    (in practice of course, the cable would probably have a weak point on one side or the other, and so that side would break first! :wink:)
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