%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 35-00-35 auf Seite 833.
%% 
%%  Copyright (C) 2016 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{352.81416pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage[dvipsnames,x11names]{pstricks}
\usepackage{multido}
\usepackage{pstricks-add}
%StopShownPreambleCommands
\begin{document}
\psset{unit=2mm}
\begin{pspicture}(-0.5,-0.5)(50,20)
\psaxes[Dx=10,Dy=5,ticksize=-3pt]{->}(0,0)(-0.5,-0.5)(50,20)
\pstVerb{
	/gg 9.82 def
	/v0 20 def
	/c0w 0.2 def
	/costhetac c0w v0 mul gg div 2 div neg def
	/sinthetac costhetac dup mul neg 1 add sqrt def
	/thetac sinthetac costhetac atan def
	/x2 gg c0w div def
}%
\multido{\nn=1+1}{15}{%
\parametricplot[linecolor=Red1,plotpoints=200,linewidth=0.5pt,plotstyle=line]{0}{60}%
  [/theta \nn\space 5 mul def
   /x1 theta sin v0 mul def
   /x2 theta cos v0 mul def ]%
  { /tt t DegtoRad c0w div def
    /zz tt x1 mul tt dup mul gg mul 2 div sub def
    t sin x2 mul c0w div zz
    zz 0 lt { /ps@Exit true def } if }%
}%
\end{pspicture}
\end{document}
