Two simple pendulums of the same length are connected by a light spring with
stiffness as shown.
For this system, determine (a) the equations of motion, (b) the natural frequencies, (c) the mode shapes, and (d) the total response of the system (for t > 0) if the initial conditions at time t = 0 are:
θ1 = θ2 = 0
θ1' = θ2' = 0
For parts (b) to (d), assume that m1 = m2 = m.