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Feb24-12, 11:14 AM
P: 19
1. The problem statement, all variables and given/known data

Hello. I have some troubles with a truss problem. In fact i believe i have correctly identified the direction of the forces involved in the rods, but i cannot identify which rod is in compression or which is in tension. Are there any tips/rules to identify only with a force diagram?

3. The attempt at a solution
Well i have resolved forces at each joint and put a direction (of the force) in the rod so that the net force at any joint is zero (Since the system is in equilibrium).

1. Direction of force at P : Horizontally to the left.
2. Direction of force at R : Vertically upwards.
3. Direction of force at Q : Vertically downwards.
4. Direction of force at S : Horizontally to the left.

However i cannot figure the least which rods are in compression or in tension.
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