%% 
%%  A DANTE-Edition example
%% 
%%  Example 34-02-1 on page 742.
%% 
%%  Copyright (C) 2010 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[]{article}
\pagestyle{empty}
\setlength\textwidth{375.57637pt}
\setlength\parindent{0pt}

\usepackage{graphicx,pst-slpe,pstricks-add}
\newpsstyle{magenta40}{fillstyle=solid,fillcolor=magenta!40}
\newpsstyle{blue40}{fillstyle=solid,fillcolor=blue!60}
\newpsstyle{Blackball}{fillstyle=ccslope,slopebegin=white,slopeend=black,
    slopecenter={0.6 0.6}}
\newpsstyle{Blueball}{fillstyle=ccslope,slopebegin=white,slopeend=blue,
    slopecenter={0.6 0.6}}
\newpsstyle{Redball}{fillstyle=ccslope,slopebegin=white,slopeend=red,
    slopecenter={0.6 0.6}}
% inclined plane
\newcommand*\VStart{10 }% starting speed in angle direction
\newcommand*\VHeight{2 }% starting height
\def\Vx{\VStart \VAngle cos mul }
\def\Vy{\VStart \VAngle sin mul }
\newcommand*\rBall{0.25 }
\newcommand*\mass{1 }

\def\SvonT#1{   % way as function of time, returns x y
  \Vx #1 mul                                             % Sx
  \Vy #1 mul \VHeight add 0.5 9.81 mul #1 dup mul mul sub } % Sy

\def\OneShot#1{
  \def\VAngle{45 }
  \pscircle[style=Blackball](! \SvonT{#1} ){\rBall}
  \def\VAngle{60 }
  \pscircle[style=Blueball](! \SvonT{#1} ){\rBall}
  \def\VAngle{75 }
  \pscircle[style=Redball](! \SvonT{#1} ){\rBall}}

\def\Axes{
  \psaxes{->}(14,8)
  \def\VAngle{45 }
  \psline[linestyle=dashed](0,\VHeight)(14,\VHeight)
  \rput(0,\VHeight){\psline[arrowscale=2]{->}(\VStart mm;\VAngle)}
  \def\VAngle{60 }
  \rput(0,\VHeight){\psline[arrowscale=2,linecolor=blue]{->}(\VStart mm;\VAngle)}
  \def\VAngle{75 }
  \rput(0,\VHeight){\psline[arrowscale=2,linecolor=red]{->}(\VStart mm;\VAngle)}}


\begin{document}
\begin{center}
\resizebox{0.9\linewidth}{!}{%
    \begin{pspicture}(-1.25,-1.25)(14.5,8.5)%
      \multido{\rTime=0.0+1.0}{30}{%
	    \OneShot{ \rTime\space 20 div }%
	  }%
	  \Axes%
    \end{pspicture}%
  }%

\medskip
\includegraphics[height=1.44em]{figures/buttons}
\end{center}
\end{document}