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Homework Help: Tension Forces and rubber bands

  1. Oct 4, 2006 #1
    I am doing some work with tension forces and applying different masses to different items like strings. We did some things with rubber bands too. I am having trouble with one of the questions posed.

    "In general, in order for a rubber band to pull back, what does it have to do?"

    I want to say there is nothing the rubber band could do. It was made that way. So I guess they're asking that if the tension of the rubber band increased it would pull back more? Or that for a rubber band to pull back it must be strecthed?
     
  2. jcsd
  3. Oct 4, 2006 #2

    radou

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    A rubber band behaves elastic up to some point.
     
  4. Oct 4, 2006 #3
    This has me stumped:

    "What change takes place in a surface so it can push back?"
     
  5. Oct 5, 2006 #4

    andrevdh

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    When a force displaces an object through a certain distance energy is expended by the person/machine or whatever exerts the force. Usually internal energy is converted to mechanical energy with such a process. We find the same situation when an eleastic is stretched - it needs to convert internal energy to mechanical energy in order to pull back on whatever is extending it. You can actually notice such a temperature increase of an elastic as a result of such a process. Try to feel the difference in temperature of an elastic on your lips before and after stretching it.
     
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