A bar (wih bending rigidity EI) is supported at A and B with length 2a. The bar is fixed at B (length=2a) with a pin support at A (length L=0). Additionally, at A is a torsion spring (spring constant Ca = EI/a) and an extension spring is attached at B (spring constant Cb = EI/(a^3)). In the unloaded state, both springs are relaxed. What is the moment in the torsion spring when a force F is applied to the middle of the beam (L=a)?