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Direction of torque vector

  1. Mar 5, 2007 #1
    1. The problem statement, all variables and given/known data
    The direction of a force is the same as the direction of the acceleration this force is creating on a moving object. And the direction of the torque? I am just questioning myself.

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Mar 5, 2007 #2
    [tex] \vec{N} = \vec{r} \times \vec{F} [/tex]

    where N is the torque, r = moment arm, F = force

    torque is perpendicular to both the moment arm, r, and the force F.
    To determine the direction you have to use the right hand rule

    your fingers point in the direction of the moment arm and the palm in the direction of the force.
  4. Mar 5, 2007 #3
    Yes, I know that. And the answer to my question is that the torque is in the direction of the change of angular velocity. Thank you, I should have worked a little more before asking.
  5. Mar 5, 2007 #4
    Are you portuguese? I ask that because I see pt on your username. :approve:
  6. Jan 11, 2008 #5
    I would like to add one thing here, in practical applications normally I consider "Clockwise" and "Anticlockwise" notation for torque are more useful. You can imagine a hanging pendulum and if you are forcing it in a way that it tends the pendulum moving in AntiClockWise direction, the torque would be ACW and considered as Positive; for the opposite condition the contrary is applied.
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