WTC  Cone Rubble


				      Vol Invisible Cone = pi Rt^2 (hci/3)/3
	     - -                     /\           7.65e+4'^3
	      |                    / |^ \  1/3 l
	      |                  /hci|/3  \                    Invisible
	      |      l=211.1'  /- - -|- - - \            - - - - - - - - - -
	      |              /       |   ^    \                   Visible
	    hci=46.53'     /         | Rt=Rb/3  \  2/3 l=140.73'
	      |          / hc=2/3hci>|  68.64'    \
	      |        /     31.0'   |              \
	      |      / < ang         |  Rb = 205.9'   \
	     _|_     - - - - - - - - - - - - - - - - - -


	      Vol Whole Cone = pi Rb^2 hci/3 = 2.07e+6'^3
	      Vol Visible Partial Cone = Vol Whole Cone - Vol Invisible Cone = 1.99e+6'^3
	      Visible Lateral Surface Area = pi 2/3*l*(Rb+Rt) = 1.22e5'^2
	      Lateral Side Length l = sqrt(Rb^2+hci^2) = 211.1'
	      Angle^ = ArcTan(Rb/hci) = 77.3 deg
	      Angle< = 90-Angle^      = 12.7 deg


				    /\
			      ##  / |  \
			    ##  / ^ |    \
			  ##  /     |      \
			##  /\      |        \l
			  /    \    |          \
			/        \  |            \
		     l/  pres sin^ \|              \
		    /               |                \
		  /                 |                  \
				   pres

 #### = 1' of WTC sliding down the lateral cone length l. The new pressure
 component is normal to the cone is pres sin^ where ^ = 77.3 deg, sin 77.3
 = .975 or only 2.5% less than flat surface. However, it's velocity component
 along the lateral cone length l is cos 77.3 = .22 or 22% slower.