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Free Body Diagram

  1. Mar 7, 2009 #1
    hey, i just want a confirm if this is correct. imagine a built-in or a fixed bar in the side of a wall. when drawing a free body diagram for the point where the wall and the bar are fixed there should be forces in both x and y and a moment of force. if we label the x and y forces on the bar, does it matter on which direction we define it as?
    Code (Text):


    ^  Ay                                                      
    |----------->    Ax        


     | Ay
    \|/ <-----------  Ax                        
    cuz, if you solve for Ax or Ay, even if it's -ve, it just means that positive motion is acting in the opposite direction....right?

    any help would b appreciated.
  2. jcsd
  3. Mar 7, 2009 #2
    Physics is invariant under coordinate transforms, especially linear non accelerating coordinate transforms like this.
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