Free Vibration
<p><b style="margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: "Helvetica Neue", Helvetica, "Nimbus Sans L", Arial, "Liberation Sans", sans-serif; vertical-align: baseline; background-image: none; background-position: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; color: rgb(34, 34, 34);">Free vibration</b><span style="color: rgb(34, 34, 34); font-family: "Helvetica Neue", Helvetica, "Nimbus Sans L", Arial, "Liberation Sans", sans-serif;"> occurs when a mechanical system is set in motion with an initial input and allowed to vibrate freely. Examples of this type of vibration are pulling a child back on a swing and letting it go, or hitting a tuning fork and letting it ring. The mechanical system vibrates at one or more of its </span><a href="https://en.wikipedia.org/wiki/Resonance" title="Resonance" style="margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: "Helvetica Neue", Helvetica, "Nimbus Sans L", Arial, "Liberation Sans", sans-serif; vertical-align: baseline; background-image: none; background-position: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(255, 255, 255); color: rgb(90, 54, 150);">natural frequencies</a><span style="color: rgb(34, 34, 34); font-family: "Helvetica Neue", Helvetica, "Nimbus Sans L", Arial, "Liberation Sans", sans-serif;"> and </span><a href="https://en.wikipedia.org/wiki/Damping" title="Damping" class="mw-redirect" style="margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: "Helvetica Neue", Helvetica, "Nimbus Sans L", Arial, "Liberation Sans", sans-serif; vertical-align: baseline; background-image: none; background-position: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(255, 255, 255); color: rgb(90, 54, 150);">damps</a><span style="color: rgb(34, 34, 34); font-family: "Helvetica Neue", Helvetica, "Nimbus Sans L", Arial, "Liberation Sans", sans-serif;"> down to motionlessness.</span></p>