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diff --git a/812/CH9/EX9.08/9_08.sce b/812/CH9/EX9.08/9_08.sce
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+//Optimum cruise speed//
+pathname=get_absolute_file_path('9.08.sce')
+filename=pathname+filesep()+'9.08-data.sci'
+exec(filename)
+//Plotting velocity with drag force
+V=175:25:455;
+
+[m n]=size(V);
+for i=1:n
+  CL(i)=2*W/p*(3600/V(i)/5280)^2/A;
+  Cd(i)=Cd0+CL(i)^2/%pi/ar;
+  Fd(i)=Cd(i)/CL(i)*W;
+  FD(i)=Fd(i)/1000;
+end
+plot(V,FD)
+xtitle('Flight speed vs thrust','Flight Speed(in mph)','Drag Force(in 1000lbf)')
+//Optimum cuise speed at speed level is obtained to be 320 mph from the graph.
+Vosl=320;
+//Ratio of speeds at 30000 ft and at sea level is given by:
+r=sqrt(1/0.375);
+//Stall speed at 30000ft is(in mph):
+Vs3=Vssl*r;
+//Optimum Cruise speed at 30000ft(in mph):
+Vo3=Vosl*r;
+printf("\n\nRESULTS\n\n")
+printf("\n\nOptimum cruise speed at sea level: %.3f mph\n\n",Vosl)
+printf("\n\nStall speed at 30000 ft: %.3f mph\n\n",Vs3)
+printf("\n\nOptimum cruise speed at 30000 ft: %.3f\n\n",Vo3)