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Homework Help: Finding Force between 2 objects

  1. Sep 26, 2010 #1
    1. The problem statement, all variables and given/known data

    Two objects are in contact on a frictionless surface. A horizontal force is applied to one object. Use m1 = 2.86 kg and m2 = 4.92 kg. If a force of 3.37 N acts between the two objects, what is the force F? I don't even know where to start! I've attempted this a numerous amount of times, and I still can't get the correct answer!


    2. Relevant equations

    F=ma

    3. The attempt at a solution
     
    Last edited: Sep 26, 2010
  2. jcsd
  3. Sep 26, 2010 #2
    So are you trying to find the force applied to the first object from whatever is pushing it and 3.37 N is the equal and opposite force applied between? If that is the case, the first thing you should do is just draw a picture with both objects then label all the forces acting on the boxes. Even if you don't know what they are. Disregard n(normal force) and w or mg (force due to gravity). They are not really a factor in this problem. You should for object 1 have a force acting against of 3.37 N(F21, force of object 2 onto object 1), as well as the force applied from whatever is pushing it (Fx). For object 2, you only have the force from object 1 of 3.37 N. Now set up your sum of forces equations.
    [tex]\Sigma[/tex]F1=m1a=Fx-F21
    [tex]\Sigma[/tex]F2=m2a=F12
    Now just do some algebra and you will be able to find the rest.
     
    Last edited: Sep 26, 2010
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