(N/A) Resonance occurs when the frequency of an external periodic force matches the natural frequency of a system,leading to a significant increase in the amplitude of oscillations.
Examples of Resonance:
$(1)$ Soldiers marching on a suspended bridge are advised to break their step. If the frequency of their marching matches the natural frequency of the bridge,resonance occurs,causing the amplitude of the bridge's vibrations to increase drastically,which can lead to the collapse of the bridge.
$(2)$ During the design of bridges,engineers ensure that the natural frequency of the bridge does not match the frequency of external forces caused by wind gusts. If these frequencies coincide,the resulting resonance can cause structural failure.
$(3)$ During an earthquake,buildings of different heights respond differently to seismic waves. Medium-height structures are often more susceptible to damage because their natural frequencies are closer to the frequencies of seismic waves,leading to resonance,whereas low-rise and high-rise structures have natural frequencies that are significantly different from the seismic wave frequencies.