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Tension question

  1. Sep 29, 2003 #1
    I believe that I was late the day my instructor explained this type of problem in class, and my textbook is worthless, so I thought I would give this a shot. It's just a tension problem, but I don't know for sure how to do it.

    A 9.00 kg handing weight is connected by a string over a pulley to a 5.00 kg block that is sliding on a flat table. If the coefficient of kinetic friction is 0.187, find the tension in the string.

    I believe that tension is the sum of all forces on the rope correct? I recall my teacher saying that we could turn a similar problem into a problem on the X-axis by making gravity a force pulling on the block in the x-direction. Anyway, I thought that I would just do 9*9.8+-(5*0.187), but that didn't seem right to me because it would seem that a frictional force would increase the tension and not decrease it? I appreciate any help.

  2. jcsd
  3. Sep 29, 2003 #2
    eh... I posted my question in the wrong section and they moved it here. I'm actually in Engineering Physics I in college, but I guess it doesn't matter where the question is if I get help.
  4. Sep 30, 2003 #3


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    Yes, frictional force would increase tension, not decrease it.
    However, if there were NO friction force, there would be NO tension on the rope, not the "9*9.9" you have. If there were no friction force the block would move freely. The tension on the rope IS the friction force.
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