1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook