Free Body Diagram: Ax & Ay Direction Matters?

[unknown_2]

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?

ie

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


            OR


 | 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.
cheers,

 

[Klockan3]

Physics is invariant under coordinate transforms, especially linear non accelerating coordinate transforms like this.