(Solved): Use the Force Method to analyse the planar truss shown in Figure 1. Select the reaction \( C_{y} \) ...

Use the Force Method to analyse the planar truss shown in Figure 1. Select the reaction \( C_{y} \) at the roller support \( \mathrm{C} \) to be the redundant. Note that \( \mathrm{N}_{1}-\mathrm{N}_{3} \) are the member forces in the statically indeterminate truss. Assume that all members have the same EA. \[ \begin{array}{l} \Delta_{C O}=\sum_{i=1}^{\text {all members }} \frac{F_{i} f_{i} L_{i}}{A_{i} E_{i}} \\ f_{c C}=\sum_{i=1}^{\text {all members }} \frac{f_{i}^{2} L_{i}}{A_{i} E_{i}} \end{array} \]