restart:
 interface(prettyprint=0, verboseproc=0);
 with(plots):
 with(plottools):
 printlevel:=0:
 print(`Parametric ball - plot: no animation - no air resistance`);
 alfa:=Pi/6:
 Htmax:=40:g:=9.81:
 V:=(sqrt(2*g^3*Htmax/(2*g^2-1)))/sin(alfa):
 tmax:=V*sin(alfa)/g: plot([2*t,V*t-0.5*g*t^2, t=0..ceil(2*V/g)]);
 print(`Parametric ball - plot: no animation - with air resistance`);
 k:=.8:
 printf("Drag factor k=%5.3f\n",k);
 plot([Htmax*exp(k*(V/g-t)),V*t-0.5*g*t^2, t=0..ceil(2*V/g)]);
 
 for i from 0 to 8 do
 k:=0.01*i:
 ranj:=Htmax*exp(k*V*sin(alfa)/g): 
 t_end:=ceil(2*V*sin(alfa)/g):
 pl:=plot([V/k*cos(alfa)*sin(k*t),V*sin(alfa)*t-0.5*g*t^2, t=0..t_end]):
 pline:=line([ranj, Htmax/3],[ranj,0]):
 printf("V=%5.3f Max height=%5.2f: time %5.3f  Range= %5.1f  Drag factor k=%5.3f\n",V,Htmax,tmax,ranj, k);
 # Why no plot output?
 plots[display](pl, pline);
 #plots[display](pl);
 end do;