frustrum

1. How to calculate the volume of a frustrum of a right circular cone with a bore radius

I have to figure out this problem. Please give calculations with a formula to solve it. Thanks If the overall length (L) is 46 cm radius 1 (R1) is 5.3 cm radius 2 (R2) is 2.8 cm and radius 3(R3) is 7.7 cm What is the Volume?
2. cone with frustrum problem.

hey all, so, I have encountered a problem in my studies that I am having trouble with. I was hoping the members of this community could help me out. The problem is based on a right cone. The cone has been sliced to create a frustrum. The height of the entire unsliced cone is 20 inches, with...
3. Volume of the frustrum is incorrect if you derive it!!!!

So most likely I am the one with a mistake...but hell I can't get it to work. I am attaching my work. So I try to derive the volume of a cylinder from the area of the circle (A(circle) = pi*r^2)....from h=0 to h=H. Same with the cone...but here we know that the radius depends on the h so...
4. Frustrum rate of change

A shock wave is advancing in the shape of a frustrum of a right circular cone. The upper radius, x of the frustrum is increasing at the rate of 2m per sec, the lower radius, y is increasing at the rate of 3m per sec, and the height, z is increasing at the rate of 1.5m per sec. Using the chain...
5. volume of a frustrum

my question is: "prove that the volume of a frustrum of a sphere of height h and end radii r1 and r2 ,is 3.14h(3(r12+r22)+h2)/6."