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Homework Help: Which direction does the normal contact force act?

  1. Mar 16, 2005 #1
    A ring of mass 0.3kg is threaded on a fixed, rough, horizontal curtain pole. A light inextensible string is attached to the ring. The string and the pole lie in the same vertical plane. The ring is pulled downwards by the string which makes an angle "A" to the horizontal, where tan A=3/4. The tension in the string is 2.5N. The ring is in equilibrium.

    This question doesnt seem that difficult, but in which direction does the normal contact force act?
  2. jcsd
  3. Mar 16, 2005 #2

    Doc Al

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    Staff: Mentor

    The contact force between the ring and the rod has two components: the component parallel to the rod, which is the friction; the component perpendicular to the rod, which is the normal force. If I picture the setup correctly, the normal force on the ring points up.
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