Two simple pendulums, each of length 0.300 m and mass 0.950 kg, are coupled by attaching a light, horizontal spring of spring constant k = 1.50 N/m⁻¹ to the masses.
(a) Determine the frequencies of the two normal modes.
(b) One of the pendulums is held at a small distance away from its equilibrium position while the other pendulum is held at its equilibrium position. The two pendulums are then released simultaneously. Show that after a time of approximately 12 s the amplitude of oscillation of the first pendulum will become equal to zero momentarily. (Assume g = 9.81 m/s⁻².)