\documentclass[crop,border=5,tikz,convert={outext=,
  command=\unexpanded{pdf2svg \infile\space\outfile\%02d.svg
    all}},multi=false]{standalone}
\usetikzlibrary{calc,patterns}

\newcommand{\markangle}[6][0.25]{
  \begin{scope}
    \clip (#2)--(#3)--(#4);
    \node (ANG) [draw, circle, minimum size=#5] at (#3){};
  \end{scope}
  \coordinate (E1) at (intersection 0 of ANG and #3--#2);
  \coordinate (E2) at (intersection 0 of ANG and #3--#4);
  \coordinate (EM) at ($ (E1)!0.5!(E2) $);
  \coordinate (EM) at ($ (EM)!#1!(#3) $);
  \node at (EM) {#6};
}

\def\a{-30}

\begin{document}
\begin{tikzpicture}[>=latex,scale=1]
  \fill[white] (-2.5,-5.6) rectangle (2.5,0.3);
  \coordinate (m) at (-90+\a:3);
  \coordinate (maxA) at (-50:3);
  \coordinate (S) at (0,-3.5);
  \coordinate (F) at ($ (0,0)!1.6!(m) $);
  \coordinate (Frad) at ($ (0,0)!1.6!(m) $);
  \coordinate (Ftan) at ($ (m)+(\a:3) $);
  \coordinate (Fel) at ($ (m)+(2,0) $);
  \coordinate (Fg) at ($ (m)+(0,-2) $);
  \fill[pattern = north east lines] (-1,0) rectangle (1,0.3);
  \fill (0,0) circle (0.5mm);
  \draw[color=red,dashed] (maxA) arc (-50:-130:3);
  \draw[semithick,dotted] (0,0)--(S);
  \shade[ball color=gray!50] (m) circle (3mm)
  node[] {$m$};
  \draw[thick] (-1,0)--(1,0);
  \markangle{S}{0,0}{m}{79}{\small $\alpha$}
  \markangle{Fg}{m}{F}{60}{\small $\alpha$}
  \draw[thick,blue!50!black] (0,0)--(m)
  node[midway,fill=white,shift={(-90+\a:0.3)},inner sep=0.8]{\small $l$};
  \draw[thick,->,black!50!green] (m)--(Fg)
  node[below,shift={(0,0.1)}]{\small $m\vec{g}$};
  \draw[thick,black!50!green,->] (m)--($(m)!(Fg)!(Frad)$);
  %node[midway,right]{$\vec{F}_\mathrm{rad}$};
  \draw[semithick,dotted,black!50!green]($(m)!(Fg)!(Ftan)$)--(Fg);
  \draw[semithick,dotted,black!50!green]($(m)!(Fg)!(Frad)$)--(Fg);
  \draw[thick,black!50!green,->] (m)--($(m)!(Fg)!(Ftan)$);
  %node[below,inner sep=1]{$\vec{F}_\mathrm{tan}$};
  \draw[color=red,very thick,<-] (m) arc (-90+\a:-90:3)
  node[midway,above]{\small $x$};
\end{tikzpicture}
\end{document}