\documentclass{article}
\usepackage{bm}% boldmath
\usepackage{pstricks}
\usepackage{pst-grad}
\usepackage{pstricks-add} % psellipsearc
\newrgbcolor{braun}{0.6 0.1 0.2}
\SpecialCoor
\parindent=0pt
\pagestyle{empty}


\begin{document}

%\psset{unit=0.6}
\begin{pspicture}(-4.5,-5)(5.5,3)
%\psgrid[subgriddiv=0,griddots=10]
\pscustom[fillstyle=solid,fillcolor=braun]{%
  \psline(2.3,0.2)(4,0.2)
  \psarcn(4,0){0.2}{90}{-90}
  \psline(4,-0.2)(2.3,-0.2)
}
\psline(0,2.5)(0.3,2.5)
\psellipse(0.3,0)(2,2.5)
\psline(0.3,-2.5)(0,-2.5)
\psellipse[fillstyle=gradient,gradangle=90,gradbegin=white,%
    gradend=braun,gradmidpoint=1](0,0)(2,2.5)
\pscustom[fillstyle=solid,fillcolor=braun]{%
  \psline(-4,0.2)(0,0.2)
  \psarcn(0,0){0.2}{90}{-90}
  \psline(0,-0.2)(-4,-0.2)
}
\psline[linecolor=white,linewidth=0.1]{->}(0,0)(2.5;-90)
\rput(-0.25,-1.5){\white\Large$\bm{\vec{r}}$}
\pscircle[fillstyle=solid](-4,0){0.2}
\psline[linewidth=0.2]{|-}(-3.5,-3)(-3.5,-0.2)
\psline[linewidth=0.2]{|-}(3.5,-3)(3.5,-0.2)
\pscustom[fillstyle=solid,fillcolor=lightgray]{%
    \psellipticarcn(0,0)(2,2.5){90}{50}
    \psline(2.25;50)(4.9,-4)(5.2,-4)(2.5;50)
    \psellipticarc(0.3,0)(2,2.5){50}{90}
}
\psline[linewidth=0.2,linecolor=red]{->}(5,-4)(5.65,-5)
\uput[0](4,-4.5){\Large $\vec{F}$}
\end{pspicture}

\end{document}