Free Body Diagram from Space Diagram

AI Thread Summary
The discussion focuses on converting a space diagram into a free body diagram, with particular attention to the forces acting at points J and E. At point J, a vertical reaction force is correctly identified, while at point E, both horizontal and vertical forces are acknowledged, although it's clarified that no horizontal force is applied. The importance of accurately representing the direction of forces is emphasized, noting that both vertical reactions at J and E should point upwards due to the downward forces in between. The conversation highlights the necessity of understanding the mechanics of the system to ensure correct force representation. Overall, clarity in force direction and application is crucial for creating an accurate free body diagram.
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Homework Statement



http://desmond.imageshack.us/Himg804/scaled.php?server=804&filename=img1.gif&res=medium
I have to change this space diagram into a free body diagram and i am struggling

Homework Equations





The Attempt at a Solution



I have put a reaction force in the the x direction at point J and a rection force in the y direction at point j aswell. I have also done the same at Point E. I don't no if this is right? I'm not sure if there is meant to be a moment force somewhere? Could anyone help?
 
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The purpose of the wheel at J is to prevent any horizontal reaction at that point, so the only external force there is vertical. Now at E, the pin will support both a horizontal and vertical force, but no moment, so forces in both directions there are correct.
 
thanks very much !
 
Are you only asked for a free body diagram?

Because, it's also important you get the vectors direction right, and this you can normally only do with calculations.

While in principle pin E supports both a horizontal and a vertical force, you can see that no horizontal force is applied at the structure. So there is no horizontal force there at E.

Also, you can see that both vertical reactions at J and E will point up, because all the other forces in between them point down.
 
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