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Homework Help: Circular Motion,Uniform motion in Vertical Circles

  1. Apr 22, 2012 #1
    1. The problem statement, all variables and given/known data

    If the object is at the top, the centripetal force (pointing as
    always towards the centre) is down and negative.
    ● If the object is at the bottom, the centripetal force is pointing up and positive


    3. The attempt at a solution
    I thought any force towards the center is always positive.Am i wrong?
     
  2. jcsd
  3. Apr 22, 2012 #2
    Depends on your coordinate system?
     
  4. Apr 22, 2012 #3
    It's called a sign convention. You may choose it to be whatever you wish but you must be consistent within each problem.
     
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