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Homework Help: Rotational Motion of an object

  1. Nov 6, 2007 #1
    I have two problems I am working on, and I have no idea about either

    1. The problem statement, all variables and given/known data

    1. A 0.400-kg object is swung in a circular path and in a vertical plane on a 0.500-m-length string. If the angular speed at the bottom is 8.00rad/s, what is the tension in the string when the object is at the bottom of the circle?

    2. At what angle (relative to the horizontal) should a curve 52 m in radius be banked if no friction is required to prevent the car from slipping when traveling at 12 m/s? (g-9.8m/s^2)

    2. Relevant equations

    1 . m(v^2/r)=T ??

    2. ?

    3. The attempt at a solution

    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Nov 6, 2007 #2
    Well, for the first problem, you'll need to relate the objects tangential speed to its angular speed. Any idea on what equation you should use? (Hint: We're dealing with circular motion).
  4. Nov 6, 2007 #3
    I have been attempting to use Vt=rw and then plugging that number into m(v^2/r) to give me the total force

    Is the tension the only force?
  5. Nov 6, 2007 #4
    The tension is not the only force, but it's the only force we're concerned with. If you mean "Vt" to be the tangential velocity, that's the correct equation.
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