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Homework Help: Circular motion and tension

  1. Feb 21, 2008 #1
    [SOLVED] circular motion and tension

    I could do this easily if it werent rotating or if it were one wire....but this is kicking my but.

    Two wires are tied to a 340 g sphere. Both wires are 1m in length and attached to a pole at lengths of .5m below and above the sphere. The sphere revolves in a hori*zontal circle at a constant speed of 7.0 m/s. What is the tension in each of the wires?

  2. jcsd
  3. Feb 21, 2008 #2
    How far is the sphere from the pole?

    How fast is it moving?

    What is the acceleration of the sphere? (magnitude and direction)

    what is the force to produce this acceleration AND counteract gravity.

    Now find 2 forces in the direction of the wires that add up to this net force.
  4. Feb 21, 2008 #3


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    There are three forces acting on the sphere, mg (gravity) pointed downward and two different tensions T1 and T2 pointed along the wires. Split all of the forces into x and y components. The sum of all the vertical components should equal zero and the sum of the horizontal components should equal the radial acceleration of the sphere.
  5. Feb 21, 2008 #4
    Thanks guys, thats exactly what i needed to figure it out! you saved me a headache on that one.
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