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Homework Help: Need help with Static Equilibrium Problem

  1. Dec 12, 2007 #1
    We put a 100 cm ruler on a table at the 50cm mark. The 0cm mark is on the table and the 100cm mark is in free air. The ruler is in static equilibrium.

    Now we place the ruler on the table at the 40cm mark, creating a torque on the ruler so that it is not balanced.

    Next attach a weightless string with some length l at some mark on the ruler.

    Then put a hammer on the string so that the head of the hammer is facing toward the ground while the bottom of the hammer is touching the ruler. (The com of the hammer is towards the table)

    Here is a diagram: http://img81.imageshack.us/img81/1984/abcqc5.png [Broken]

    Can someone tell me what all the forces acting in this system are? Thanks
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Dec 12, 2007 #2
    Well, if you are considering the "system" as acting as a single object, the weight (combined total of meter stick + hammer) is acting downward and the normal force (from the table) is upwards.

    If you are breaking it down into forces on individual objects...
    hammer - weight downward, tension upward
    meterstick - weight downward, tension downward, normal force upward
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