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Homework Help: Beam Problem

  1. Jun 21, 2007 #1
    1. The problem statement, all variables and given/known data
    A 24 kg beam of length 2.4 m leans against a smooth wall. A horizontal rope is tied to the wall and holds the beam on a frictionless floor. The beam makes an angle of 55 degrees with the floor. WHat is the tension in the rope? (The rope is on the floor.

    2. Relevant equations
    torque=force|| x distance

    3. The attempt at a solution
    (Torque at the bottom of the beam)
    24kg x 9.8 x cos55 x 1.2m + T x cos35 x 2.4m = F(normal1) x cos55 x 2.4m

    (torque at the top)
    24kg x 9.8 x cos55 x 1.2m = F(normal2) x cos35 x 2.4m + Ff x cos55 x 2.4m

    Now what?
  2. jcsd
  3. Jun 21, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    I don't understand your equations. Please identify all the forces acting on the beam: where they act, their direction and symbol.

    Also realize that setting net torque equal to zero is only one of the conditions for equilibrium. What about the net force?
    Last edited: Jun 21, 2007
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