This Lesson (Solved problems on volume of cones) was created by by ikleyn(52786): View Source, Show About ikleyn:
Solved problems on volume of cones
In this lesson you will find typical solved problems on volume of cones.
The theoretical base for these problems is the lesson Volume of cones under the topic Volume, metric volume of the section Geometry in this site.
Problem 1
Find the volume of a cone if the base radius of the cone is of 4 cm and the height of the cone is of 9 cm.
Solution
Apply the formula for the volume of a cone. The volume is
= . = .. = .. = = 150.8 (approximately).
Answer. The volume of the cone is 150.8 (approximately).
Problem 2
Find the volume of a combposite solid body which comprises of two identical cones joined base to base (Figure 3), if their common base radius is of 4 cm and the height
is of 3 cm each.
Solution
We are given a 3D body comprised of two identical cones whose bases are joined and
overposed each to the other (Figure 3).
The volume of each single cone is
= = .. = .
The volume of the given composite body is doubled this value, i.e.
= = = 3.14159*24 = 100.53 (approximately).
Figure 3. To the Problem 2
Answer. The volume of the given composite body is 100.53 (approximately).
Problem 3
A composite solid body comprises of the cone and the cylinder that have the same base radius measure. The cone and the cylinder are joined base to base in a way that the centers of their bases coincide (Figure 4). Find the volume of the given body if the common base radius is of 4 cm and the height of the cone and the cylinder is of 3 cm.
Solution
We are given a 3D body comprised of the cone and the cylinder with identical base
radii measures whose bases are joined and overposed each to the other (Figure 4).
The volume of the cone is
= = .. = = 50.265 (approximately).
The volume of the cylinder is
= = .. = = 150.8 (approximately).
The total volume of the composite solid body is the sum of these values
Answer. The volume of the composite body is 201.06 (approximately).
Problem 4
Find the volume of a body (a truncated cone) obtained from a cone with the base radius of 4 cm and the height of 6 cm after cutting off the part of the cone by the plane parallel to the base in a way that the cutting plane bisects the height of the original cone (Figure 5).
Solution
The strategy solving this problem is to find first the volume of the entire cone with
the base radius of 6 cm and the height of 8 cm and then to distract the volume
of the cone with the base radius of 3 cm and the height of 4 cm.
The volume of the original entire cone is , where = 4 cm is the cone base
radius and = 6 cm is the cone height. So, the volume of the cone is
= = .
The small cone has the base radius of = 2 cm and the height of = 3 cm.
Therefore, the volume of the small cone is = .
Figure 5. To the Problem 4
Thus the volume of the truncated cone under consideration is - = = 3.14159*28 = 87.96 (approximately).
Answer. The volume of the truncated cone is 87.96 (approximately).
My lessons on volume of cones and other 3D solid bodies in this site are