ClearAll;
$DefaultFont = {"Times-Roman",10};
Needs["Graphics`Graphics`"];
tfoc = 0.305; tr = 0.3175;
K = 0.07; L1 = 1.01; r1 = K/(L1 GoldenRatio);
L2 = 117; r2 = K/(L2 GoldenRatio);
c = 7/(100 GoldenRatio);
cc = 180/Pi;

V[t_]:= 5 (8779 + 70560 t - 924000 t^2 + 3136000 t^3 - 3360000 t^4)/432;
v[t_]:= 350(10 t - 3)(20 t - 1)(7 - 20 t)/9;
plV = Plot[V[t],{t,0.28,0.35},PlotPoints->100];
phi[t_]:= cc ArcTan[c v[t]];
xticks = {0.285,0.315,{topt,"s"},0.345};
yticks = {49.1,49.5,49.9};

opt = FindMinimum[-phi[t],{t,0.32,0.33}];
topt = t/.opt[[2]];
a = -opt[[1]];
line = Graphics[{Dashing[{0.001,0.01}],
	Line[{{tfoc,0},{tfoc,phi[tfoc]}}]}];
circ = Graphics[Disk[{topt,a},0.0005{1,1/r2}],
	AspectRatio->Automatic];
ucirc = Graphics[Disk[{topt,V[topt]},0.0005{1,1/r1}],
	AspectRatio->Automatic];
	
yfoc = V[tfoc];
gradfoc = Tan[phi[tfoc]/cc]/c;
yr = yfoc + gradfoc(tr-tfoc);
ts = tfoc + (tr-tfoc)Sec[phi[tfoc]/cc];
linedot = Graphics[{Dashing[{0.001,0.01}],
				  Line[{{tfoc,yfoc},{tr,yr}}]}];
linedash = Graphics[{Dashing[{0.01,0.01}],
				  Line[{{tfoc,yfoc},{ts,yfoc}}]}];
sector = Graphics[{GrayLevel[0.65],Disk[{tfoc,yfoc},
			{tr-tfoc,(tr-tfoc)/c},{0, phi[tfoc] Degree}]}];
text = Graphics[Text["21 degrees",{tfoc+0.018,yfoc+0.05}]];

upper = Show[plV, ucirc, sector,linedot,linedash,text,
	PlotRange -> {{0.28,0.35},{49,50.01}},AxesLabel->{"t","V"},
	PlotLabel->"(a) Volume of Blood in Left Ventricle (ml)",
	AxesOrigin->{0.2795,48.99},
	Ticks->{xticks,yticks}];
angle = Plot[phi[t],{t,0.7/25,7/20},PlotPoints->100];
lower = Show[angle,circ,line,AxesLabel->{"t",FontForm[q,{"Symbol",9}]},
	PlotRange -> {{0.28,0.35},{-66,51}},
	AxesOrigin->{0.2795,-0.01},
	PlotLabel->"(b) Elevation of Graph (degrees)",
	Ticks->{xticks,Table[20(i-4),{i,6}]}];
Show[GraphicsArray[{{upper},{lower}},PlotLabel->"Figure 14.2"]]