Resonance is a process of maximum transfer of energy between two systems: one is the source and the other the receiver. This is happening only the frequency of the source = frequency of the receiver. You need to identify in yours examples the source and the receiver.
- What is the source and the receiver on a tuning fork?
- When soldiers march on a bridge or a heavy wind blowing at certain resonance frequency of a bridge can make the bridge vibrate at very large amplitude causing it to fail. What would the source and receiver be in this example?