Determine the effective stiffness of the system shown in Fig. P2-52, in terms of the displacement x.

We can determine the effective stiffness by assuming a small force Fm has been
applied at mass mso as to displace the equilibrium position by x units to the left like the
figure suggests. I am going to follow the assumption that ba  . In order to ease
communication, let´s begin by naming some points in the original figure. Let PQ be the bar that
has a pivoting fixed point O around which it can turn. The small displacement x at mass m is
the same as in P, but through bar PQ pivoting at O, it creates a displacement of y units to the
right at Q.
The diagram below shows PQ at a “vertical” position and also at an “inclined”...