somethin.tex

\begin{equation}
SE_{12} = mg\sin{\theta}
\end{equation}

\begin{equation}
SE_{22} = mg\cos{\theta}
\end{equation}

\begin{equation}
F_{11} = k_{11}r
\end{equation}

\begin{equation}
p_{23} = mv_{23}
\end{equation}

\begin{equation}
v_{13} = p_{13}/m
\end{equation}

\begin{equation}
\omega_{32} = p_{23}/J_{23}
\end{equation}

\begin{equation} \label{side-spring-force}
F_{41} = k_{41}(\frac{l_{1}}{\sin{\theta}} - l_{0})
\end{equation}