<?xml version="1.0" encoding="UTF-8"?>

<record version="1" id="1466">
 <title>Period Derivation for the Simple Harmonic Oscillator</title>
 <name>PeriodDerivationForTheSimpleHarmonicOscillator</name>
 <created>2026-10-10 18:30:30</created>
 <modified>2026-10-10 18:30:30</modified>
 <type>Derivation</type>
<parent id="58">simple harmonic oscillator</parent>
 <creator id="1" name="bloftin"/>
 <modifier id="1" name="bloftin"/>
 <comment>added the tikz source for the figure</comment>
 <author id="1" name="bloftin"/>
 <classification>
	<category scheme="pacs" code="40."/>
 </classification>
 <related>
	<object name="SimpleHarmonicOscillator"/>
	<object name="Oscillation"/>
 </related>
 <keywords>
	<term>Periodicicty</term>
	<term>Period</term>
	<term>Sine</term>
	<term>Simple Harmonic Oscillator</term>
 </keywords>
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 <content>\section*{Period Derivation for the Simple Harmonic Oscillator}

A solution for the simple harmonic oscillator is 

\begin{equation}
x = A \sin (\omega t + \phi)
\end{equation}

The sine function as a function of $\omega t$ is shown in figure 1.

\begin{center}
\includegraphics{sine_function.png}

{\small Figure1. Sine function.}
\end{center}

One can see that the sine function repeats every $2\pi$.  Periodicicty was defined in Oscillations as a function that is equal to itself at $t+T$,

\begin{equation}
f(t+T) =f(t)
\end{equation}

Therefore, the arguments to the sine function must be equal to itself again at $2\pi$  (plug in $t+T$ in for $t$).

\begin{equation}
\omega (t+T) + \phi = \omega t + \phi + 2\pi
\end{equation}

expand paranthesis and subtract each side by $\phi$

\[ \omega t + \omega T =  \omega t + 2\pi \]

$\omega t$ cancels to leave

\[ \omega T =  2\pi \]

Finally, rearrange to get the eqaution for period

\begin{equation}
T= \frac{ 2\pi }{\omega}
\end{equation}

\begin{thebibliography}{9}


\bibitem{French}
A. P. French,
\emph{Vibrations and Waves},
W. W. Norton, 1971.

\bibitem{Loftin}
PhysicsLibrary,
\emph{Oscillation}.

\end{thebibliography}</content>
</record>
