Changes

Resonance was discovered by [[Galileo Galilei]] with his investigations of [[pendulum]]s beginning in 1602.

Resonance was discovered by [[Galileo Galilei]] with his investigations of [[pendulum]]s beginning in 1602.

== 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 resonance 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.

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 resonance 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.