Solve 4 Unknowns: Statics Question

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Discussion Overview

The discussion revolves around a statics problem involving four unknown forces (Ax, Ay, Cx, and Cy) in a mechanical system. Participants explore how to approach solving for these unknowns given the constraints of equilibrium, specifically focusing on the equations of static equilibrium.

Discussion Character

  • Technical explanation, Debate/contested, Homework-related

Main Points Raised

  • One participant questions the ability to solve for four unknowns with only two equations derived from the sum of forces in the x and y directions being equal to zero.
  • Another participant suggests that the net moment on each strut should also be considered, implying additional equations may be available.
  • A different participant asserts that there are only two unknowns at the supports (forces A and C) and emphasizes that the other unknowns should be expressed in terms of these two forces.
  • One participant expresses uncertainty and requests hints for progressing with the problem.
  • Another participant recommends drawing the triangle of forces for joint B as a potential strategy for visualizing the problem.
  • A later reply indicates that there are two additional equations relating Ax to Ay and Cx to Cy, suggesting that these relationships could aid in solving the problem.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the number of equations available or the best approach to solve for the unknowns. Multiple competing views on the methodology remain present.

Contextual Notes

Participants express varying assumptions about the relationships between the unknown forces and the equations of equilibrium, indicating potential limitations in their approaches.

Who May Find This Useful

Students or individuals interested in statics problems, particularly those involving equilibrium and force analysis in mechanical systems.

Ry122
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[PLAIN]http://img38.imageshack.us/img38/6997/forces99.jpg

I'm unsure how to go about solving this. There's 4 unknowns. Ax Ay Cx and Cy but isn't there only 2 equations (sum of forces in x and y direction are equal to 0) that can be created in this situation?
 
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The net moment on each strut should be 0 as well.
 
No, there are two unknowns, the forces A and C at the supports. There are two equations. Every one of your "unknowns" must be written in terms of A and C (i.e. their projections onto the x and y-axis).
 
I am also stuck on this question. any hints would be much appreciated :)
 
Draw the triangle of forces for joint B
 
You have two additional equations. One relates Ax and Ay. The other relates Cx and Cy. Can you sketch in the expected directions of the reactions?
 

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