Resonance - Examples

Examples

One familiar example is a playground swing, which acts as a pendulum. Pushing a person in a swing in time with the natural interval of the swing (its resonant frequency) will make the swing go higher and higher (maximum amplitude), while attempts to push the swing at a faster or slower tempo will result in smaller arcs. This is because the energy the swing absorbs is maximized when the pushes are 'in phase' with the swing's oscillations, while some of the swing's energy is actually extracted by the opposing force of the pushes when they are not.

Resonance occurs widely in nature, and is exploited in many man-made devices. It is the mechanism by which virtually all sinusoidal waves and vibrations are generated. Many sounds we hear, such as when hard objects of metal, glass, or wood are struck, are caused by brief resonant vibrations in the object. Light and other short wavelength electromagnetic radiation is produced by resonance on an atomic scale, such as electrons in atoms. Other examples are:

Mechanical and acoustic resonance

• the timekeeping mechanisms of modern clocks and watches, e.g. the balance wheel in a mechanical watch and the quartz crystal in a quartz watch
• the tidal resonance of the Bay of Fundy
• acoustic resonances of musical instruments and human vocal cords
• the shattering of a crystal wineglass when exposed to a musical tone of the right pitch (its resonant frequency)

Electrical resonance

• electrical resonance of tuned circuits in radios and TVs that allow radio frequencies to be selectively received

Optical resonance

• creation of coherent light by optical resonance in a laser cavity

Orbital resonance in astronomy

• orbital resonance as exemplified by some moons of the solar system's gas giants

Atomic, particle, and molecular resonance

• material resonances in atomic scale are the basis of several spectroscopic techniques that are used in condensed matter physics.
  • Nuclear magnetic resonance
  • Mössbauer effect
  • Electron spin resonance.