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Homework Help: Rotating barbell?

  1. Apr 4, 2009 #1
    1. The problem statement, all variables and given/known data

    A barbell consists of two small balls, each with mass 550 grams (0.55 kg), at the ends of a very low mass rod of length d = 20 cm (0.2 m). The center of the barbell is mounted on the end of a low mass rigid rod of length b = 0.3 m (see Figure), and this rod rotates counterclockwise with angular speed 110 rad/s. In addition, the barbell rotates clockwise about its own center, with an angular speed 90 rad/s.

    (a) Calculate Lrot (both magnitude and direction).
    (b) Calculate Ltrans, B (both magnitude and direction).
    (c) Calculate Ltot, B (both magnitude and direction).

    2. Relevant equations

    3. The attempt at a solution

    i dont know where to start because it is rotating while it is moving a distance at the same time?!
  2. jcsd
  3. Apr 4, 2009 #2
    I don't see a figure. Are the two rotations along the same axis?
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