model BouncingBall "The 'classic' bouncing ball model" 
  type Height=Real(unit="m");
  type Velocity=Real(unit="m/s");
  parameter Real e=0.8 "Coefficient of restitution";
  parameter Height h0=1.0 "Initial height";
  
  Height h "Height";
  Velocity v(start=0.0, fixed=true) "Velocity";
  
initial equation 
  h = h0;
  
equation 
  v = der(h);
  der(v) = -9.81;
  
  when h<0 then
    reinit(v, -e*pre(v));
  end when;
  
  annotation (experiment(StopTime=3.5, NumberOfIntervals=5000));
end BouncingBall;