ClearAll;
$DefaultFont = {"Times-Roman",10};
Needs["Graphics`Graphics`"];
q1[t_]:= 350(3 - 10 t)(20 t - 1)(7 - 20 t)/9;
q2[t_]:= -1632000(1 - 30 t/23)(t - 2/5)(3/4 - t)/49;
q3[t_]:= -1120000(1 - 12 t/11)(t - 3/4)(9/10 - t)/6;

q[t_]:= Which[t<=1/20,0,t<=7/20,q1[t],t<=2/5,0,
						 t<=3/4,q2[t],t<=9/10,q3[t]];
qplus[t_]:= Max[q[t],0];
qminus[t_]:= Min[q[t],0];

qplot = Plot[q[t],{t,0,9/10}];
qpl = Plot[qplus[t],{t,0,9/10}];
qmin = Plot[qminus[t],{t,0,9/10}];

flow = Show[qplot,AxesLabel->{"t"," "},
	PlotLabel->"Ventricular Outflow (ml/s)",
	Ticks->{Join[{{0.2,0.2},{0.5,0.5},{0.8,0.8}},
	Table[{0.05i," "},{i,17}]],{-200,0,200,400}},
	PlotRange->{{0,9/10},{-320,480}}];
flowpl = Show[qpl,AxesLabel->{"t"," "},
	PlotLabel->"Nonnegative component (ml/s)",
	Ticks->{Join[{{0.2,0.2},{0.5,0.5},{0.8,0.8}},
	Table[{0.05i," "},{i,17}]],{-200,0,200,400}},
	PlotRange->{{0,9/10},{-320,480}}];
flowm = Show[qmin,AxesLabel->{"t"," "},
	PlotLabel->"Nonpositive component (ml/s)",
	Ticks->{Join[{{0.2,0.2},{0.5,0.5},{0.8,0.8}},
	Table[{0.05i," "},{i,17}]],{-200,0,200,400}},
	PlotRange->{{0,9/10},{-320,480}}];
Show[GraphicsArray[{{flow},{flowpl},{flowm}}],
		PlotLabel->"Figure 8.5"]