A rigid rod (AB) has length L and is subjected to a vertical load P as shown. It is supported by a flexible strut (BC) that has a modulus E and cross-sectional area A. Neglect the self weight of AB and BC compared to P. Points A, B, and C are 2-D (frictionless) hinges. rigid. L B flexible strut (a) Derive the potential energy II for the system. (b) Using the given parameters, define suitable dimensionless variables to create a dimensionless potential energy II. (c) Find all equilibrium solutions. (d) Sketch them. (Hint: consider a linear expansion for P(0) about a suitable point.) (e) Determine the stability of all equilibrium branches. Find any critical points and classify them.