A metallic right circular cone 20 cm high and whose vertical angle is
is cut into two parts at the middle of its height by a plane parallel to its base. If the frustum so obtained be drawn into a wire of diameter
cm, find the length of the wire.
Solution:
Height of right circular cone
cm
Right circular cone is cut into two parts at the middle. We get right circular cone of height 10 cm and frustum of cone of height 10 cm.
Height of the frustum of the cone
cm
Let radius of the upper end of the frustum of the cone
cm
Let radius of the lower end of the frustum of the cone
cm
We can find
from
.
tan
cm
Similarly, we can find
from
tan
cm
Let length of wire
cm
Radius of wire
cm
According to given condition we have volume of the frustum of the cone = Volume of wire
cm =7964.44 m
Leave a Reply