Therefore,,by divergence theorm.
= --(1) where z1=z-coordinate of the centroid of the cone
or so that
Now we know that represents a right circular cone whose vertex is (0,0,0) and whose axis is OZ,base is a circle with equation
Here the radius of the cone =4 and height of the cone =4.If ZG be the centroid of the cone,then and V=volume of the cone =