What phenomenon occurs when a system is driven at its natural frequency?

When a system is driven at its natural frequency, it experiences resonance, which is the phenomenon characterized by an increase in the amplitude of oscillation. Every system that oscillates has a natural frequency, determined by its physical properties such as mass and stiffness. When an external force is applied at this frequency, it can constructively interfere with the system's natural oscillation, causing the oscillation amplitude to grow significantly.

This effect can be observed in various systems, such as swinging a child on a swing or engineering structures that must withstand vibrations. If the frequency of the driving force matches the natural frequency of the system, energy is efficiently transferred, leading to large oscillations which can sometimes result in failure if the amplitude becomes excessive.

Understanding resonance is crucial in fields ranging from engineering to music, as it illustrates how systems can interact with external forces in profound ways.