# Draw a pulley system

Consider: I need to draw a pulley system as in the figure. How can I do that?

\begin{tikzpicture}
\fill[pattern=north east lines] (-3,0) rectangle (3,.3);
\draw(-3,0)--(3,0);
\draw(-2.5,0)--(-2.5,-2.4);
\draw(2.5,0)--(2.5,-1);

\draw[fill=white] (-2.5,-2.4) circle (.3);
\draw[fill=white] (2.5,-1) circle (.3);
\draw[fill=white] (0,-3) circle (.153);

\draw
(2.5,-1) coordinate (a) node[right] {}
-- (0,-3) coordinate (b) node[left] {}
-- (0,-2.75) coordinate (c) node[above right] {}
pic["$\beta$", draw=orange, <->, angle eccentricity=1.2172, angle radius=.51cm]
{angle=a--b--c};

\draw
(0,-2.75) coordinate (a) node[right] {}
-- (0,-3) coordinate (b) node[left] {}
-- (-2.5,-2.4) coordinate (c) node[above right] {}
pic["$\alpha$", draw=orange, <->, angle eccentricity=.72172, angle radius=.751cm]
{angle=a--b--c};
\draw[dashed] (0,-3)--(0,-1);
\draw[fill=white] (-2.5,-2.4) circle (.3);
\draw[fill=white] (2.5,-1) circle (.3);

\draw[fill=white] (0,-3) circle (.153);

\end{tikzpicture}


In order to compute the tangents it is advantageous to make the circles nodes and to use tangent cs:, which comes with calc. And the angles can be conveniently drawn with the angles library, where quotes makes it somewhat simpler to add \alpha and \beta.

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{patterns,calc,angles,quotes}
\begin{document}
\begin{tikzpicture}
\fill[pattern=north east lines] (-3,0) rectangle (3,.3);
\begin{scope}[thick]
\draw(-3,0)--(3,0);

\path (-2.5,-2.4) node[circle,draw,inner sep=.3cm] (L){}
(2.5,-1) node[circle,draw,inner sep=.3cm] (R){}
(0,-3) node[circle,draw,inner sep=.153cm,label=below:$m$] (M){};
\draw (L.north) -- (L.north|-0,0) (R.north) -- (R.north|-0,0);
\draw[dashed] (M) -- (0,-1)coordinate (M1);
\draw (M)  -- (tangent cs:node=L,point={(M.center)},solution=1) coordinate (L1)
let \p1=($(L1)-(L.center)$),\n1={atan2(\y1,\x1)},\n2={veclen(\y1,\x1)} in
arc(\n1:180:\n2) -- ++(0,-1.5) node[below,draw]{$m_1$};
\draw (M)  -- (tangent cs:node=R,point={(M.center)},solution=2) coordinate (R1)
let \p1=($(R1)-(R.center)$),\n1={atan2(\y1,\x1)},\n2={veclen(\y1,\x1)} in
arc(\n1:00:\n2) -- ++(0,-1.5) node[below,draw]{$m_2$};
\end{scope}
\path pic [draw,angle radius=0.5cm,"$\alpha$",angle eccentricity=1.5] {angle = M1--M--L1}
pic [draw,angle radius=0.7cm,"$\beta$",angle eccentricity=1.5] {angle = R1--M--M1} ;
\end{tikzpicture}
\end{document} 