Question

a cone of radius 10 cm is divided into two parts by drawing a plane through the midpoint of its axis , parallel to its base . compare the volume of the two parts

Answer 1

Let R be the radius at the base, and r be the radius at the parallel plane.

R=10 and r=R/2=5

Using the formula for the frustrum of the lower cone, we get;

V=175πh/6

Using the formula for the upper cone, we get;

v=25πh/6

Therefore;        V:v
              175πh/6:25πh/6
                         7:1