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Equilibrium in the Human Body using Torque

  1. Jun 7, 2010 #1
    In the movie Terminator, Arnold Schwarzenegger lifts someone up by the neck and, with both arms fully extended and horizontal, holds the person off the ground. If the person being held weighs 650 N, is 60 cm from the shoulder joint, and Arnold has an anatomy analogous to that in the figure below, what force must each of the deltoid muscles exert to perform this task? [Hint: The weight of the arm is 30.0 N and its center of gravity is at the elbow joint, 27.5 cm from the shoulder joint.]

    Picture of the arm: http://s935.photobucket.com/albums/ad199/kemcco1955/?action=view&current=Physics.gif&newest=1

    So far:Torque = Fm(sin15)(.12) - (650)(.6) - (30)(.275)
    = Fm(sin15)(.12) – 398.25
    Fm = 12822.67

    Torque = Fsy+(30)(.155) + (650)(.48)-Fm(sin15)(.12)
    Fsy = 81.6

    Fx = (12822.67)(cos15) = 12385.75
    Fs^2 = (12385.75)^2 + (81.6)^2 = 12386 N = 12.386 kN
  2. jcsd
  3. Jun 8, 2010 #2
    Homework? There's a separate section for that, I think.
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