2 files changed, 25 insertions, 0 deletions
diff --git a/3886/CH9/EX9.13/9_13.sce b/3886/CH9/EX9.13/9_13.sce
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index 000000000..ad31e5007
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+++ b/3886/CH9/EX9.13/9_13.sce
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+//Polar moment of inertia
+//Refer fig.9.38
+//section can be divided into three triangles
+A1=80*12  //mm^2
+A2=(150-22)*12  //mm^2
+A3=120*10  //mm^2
+A=A1+A2+A3  //mm^2
+Ixx=((80*12^3)/12)+(960*74.22^2)+((12*128^3)/12)+(1536*4.22^2)+((120*10^3)/12)+(1200*64.78^2)  //mm^4
+Iyy=((12*80^3)/12)+((128*12^3)/12)+((10*120^3)/12)  //mm^4
+//Polar moment of Inertia (Izz)
+Izz=Ixx+Iyy  //mm^4
+kxx=sqrt(Ixx/A)  //mm
+Kyy=sqrt(Iyy/A)  //mm  The answer provided in the textbook is wrong
+printf("\nIzz=%.2d mm^4\nkxx=%.2f mm\nkyy=%.2f mm",Izz,kxx,kyy)
+
+
+
+
+
diff --git a/3886/CH9/EX9.13/9_13.txt b/3886/CH9/EX9.13/9_13.txt
new file mode 100644
index 000000000..553fb7d87
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+++ b/3886/CH9/EX9.13/9_13.txt
@@ -0,0 +1,6 @@
+ 
+--> exec('E:\My program EM\9. Centroid and moment of inertia\9.13.sce', -1)
+
+Izz=14440459 mm^4
+kxx=58.09 mm
+kyy=31.21 mm
+\ No newline at end of file