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Homework Help: PHysics PHysics Physics Physics Torque

  1. Nov 3, 2004 #1
    Here is my problem:
    A 2.50g particle moves in a circle of radius 3.00m. The magnitude of its angular momentum relative to the center of the circle depends on time according to L = (3.5 Nm)t. Find the magnitude of the torque acting on the particle.

    I know that:
    T = F L
    where T = torque
    F is the force
    L is angular momentum
    I feel like this problem is more algebraic than anything. I just need something stable to start from. Pleeeeeeeeaaaase Heeeeeeelp!!
  2. jcsd
  3. Nov 3, 2004 #2


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    Science Advisor
    Gold Member

    I'm afraid your equation is wrong. You may be thinking of [tex]\vec{\tau} = \vec{r}\times\vec{F} [/tex], where r is the moment arm (and its a vector equation). What you need to use is the idea that the rate of change of angular momentum is equal to the torque. I hope that helps.
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