\documentclass[convert=true,convert={convertexe={convert},density=1200,outext=.png}]{standalone}

\input{figsDefs.tex}

\begin{document}
	
\begin{tikzpicture}%
	\path (0,0) node[coordinate] (P1) {};
	\path (3,-2) node[coordinate] (P2) {};
	\path ($(P2)-(P1)$) node[coordinate] (d) {};
	\draw[-,dashed,dirCol] ($(P1)-.3*(d)$) -- ($(P2)+.3*(d)$);
	% m1
	\draw[thick,fill] (P1) circle (0.1) node[below left] {$1$};
	% m2
	\draw[thick,fill] (P2) circle (0.1) node[above right] {$2$};
	% forces
	\draw[->,>=latex,thick,forceCol] (P1) -- +($0.4*(d)$) node[above right,pos=0.6] {$\vec{F}_{2\rightarrow 1}$};%
	\draw[->,>=latex,thick,forceCol] (P2) -- +($-0.4*(d)$) node[below,pos=0.6] {$\vec{F}_{1\rightarrow 2}$};%
\end{tikzpicture}%

\end{document}