Four physical pendula are coupled by three springs. Energy is transferred from one pendulum to another.
The pendula can be swung without springs to show the natural frequency of the pendulum.The masses can be moved up and down to vary the frequency of the pendulum.The springs can be attached or not between the pendula.One pendulum can be driven to show resonance with the other pendula.
The pendulum can be driven by the Shive oscillator (2).
