Question

State the cause of resonance.

Answer 1

Resonance occurs when an object with certain frequency is closer to another object whose natural frequency is equal to the frequency of the first object. It occurs when amplitude of an object’s oscillations is increased by the matching vibrations of another object.

Complete answer:
An object free to vibrate, vibrates at a specific rate called the object's natural or resonant frequency. This object will vibrate abnormally or strongly when it is subjected or exposed to regular vibrations or frequencies close to its natural frequency. Such a phenomenon is called resonance. The resonant frequency of the object will depend on the size, shape, and composition of the object.

Additional information:
The frequencies when the amplitude is maximum relatively are known as resonant frequencies. When such phenomena occur, large amplitudes are produced which results in huge vibrational energy release. Best and easiest example is a playground swing. Pushing the swing in time with the natural interval of the spring makes it go higher and higher until maximum amplitude is attained. If we try to push it at a faster or slower tempo, the swing doesn’t go too far. This is because at natural frequency, the swing absorbs the maximum energy to produce maximum amplitude.

Note:
There are many cases in history where this phenomenon caused disasters. One of the examples is Tacoma narrows bridge collapse in the United states. Usually, a bridge collapse occurs when the surrounding frequency matches with the bridge’s frequency. In this situation, the oscillation generates at an atomic level and when the energy at this level surpasses the load limit, it loses structural integrity.