QUESTION $2$

The plane truss shown on Figure $2$ below is pinned at A and supported by pin$-$rollers at $F.$ The truss is subjected to loading as shown on the Figure. The truss members are all made from steel with Young's modulus of $200$GPa and cross$-$sectional area of $600m{m}^2.$ Member C$.$G is the redundant member and was fabricated $5mm$ too short.

a$)$ Using Strain Energy method, calculate the force in the redundant member.

b$)$ Calculate the force in each member of the truss

$W=\frac{-{\displaystyle \underset{?}{\overset{?}{}}}\frac{Ffl}{AE}}{{\displaystyle \underset{?}{\overset{?}{}}}\frac{f^{2}L}{AE}}$