\begin{equation} \vec{ \textbf{F}}_{net} = \vec{ \textbf{F}}_1 + \vec{ \textbf{F}}_2 + \vec{ \textbf{F}}_3 + ... + = \sum \vec{ \textbf{F}} \tag{5.1} \end{equation} \begin{equation} \sum \vec{ \textbf{F}} = \textbf{0} \qquad \textnormal{(body in equilibrium)} \tag{5.2} \end{equation} \begin{equation} \sum F_{x} = 0 \qquad \sum F_{y} = 0 \qquad \textnormal{(body in equilibrium)} \tag{5.3} \end{equation} \begin{equation} \Big| \sum \vec{ \textbf{F}} \Big| = ma \tag{5.4} \end{equation} \begin{equation} \sum \vec{ \textbf{F}} = m\vec{ \textbf{a}} \tag{5.5} \end{equation} \begin{equation} \sum F_{x} = ma_x \qquad \sum F_{y} = ma_y \qquad \sum F_{y} = ma_z \end{equation} \begin{equation} w = mg \tag{5.6} \end{equation} \begin{equation} \vec{ \textbf{w}} = m\vec{ \textbf{g}} \tag{5.7} \end{equation} \begin{equation} \vec{ \textbf{F}}_{ \, \textnormal{A on B}} = - \vec{ \textbf{F}}_{ \, \textnormal{ B on A}} \tag{5.8} \end{equation}
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