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Homework Help: Static Equilibrium. Man on Ladder

  1. Jan 10, 2010 #1
    1. The problem statement, all variables and given/known data
    A 9.8 m ladder whose weight is 257 N is
    placed against a smooth vertical wall. A
    person whose weight is 464 N stands on the
    ladder a distance 1.9 m up the ladder. The
    foot of the ladder rests on the floor 7.056 m
    from the wall.
    Calculate the force exerted by the wall.
    Answer in units of N.
    Calculate the normal force exerted by the
    floor on the ladder.
    Answer in units of N.

    2. Relevant equations
    Tnet = 0
    Fnet = 0

    3. The attempt at a solution
    I know I need to pick a point of rotation. I figured I would pick the bottom of the ladder where it makes contact with the floor. That will eliminated the torque due to the friction force and the normal force between the ladder and the floor. The other forces are the weight of the ladder, weight of the man, and the friction force of the ladder and wall. I'm kind of lost now.
  2. jcsd
  3. Jan 10, 2010 #2
    Have you set up a system of equations? You should have an equation for forces in the x-direction, one for forces in the y-direction, and one for torque.
  4. Jan 10, 2010 #3
    X: Fwmanx + Fwladderx = Fwall
    Y: Fwmany + Fwladderx = Fn
    Torque: I'm confused on how to determine clockwise or Counterclockwise Torque.
  5. Jan 11, 2010 #4
    I figured it out thanks
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