1. Apr 5, 2008 #1

   checkmarks

   

   1. The problem statement, all variables and given/known data
   An object of mass 12.5 kg hangs from very light pulleys as shown here:
   http://i26.tinypic.com/24lq5b4.jpg
   What force must be applied to the rope so that the mass stays at rest?
   
   2. Relevant equations
   Fnet = ma.....
   
   3. The attempt at a solution
   I am really clueless when it comes to this question. I know the net force must be 0 because there is no acceleration occuring b/c it must be at rest. Please help.

    

   checkmarks, Apr 5, 2008
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3. Apr 5, 2008 #2

   magda3227

   

   You are correct by saying that the net force must be 0, since the system will be in static equilibrium.
   Try drawing a free body diagram for each pulley.
   If you correctly label the tensions in the strings and sum up the forces in both the x and y directions, the problem will become much easier.

    

   magda3227, Apr 5, 2008

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