Needing help from a resident math wizard

[deaconjim]

I'm working on a small project, and I need to find a mathematical formula for a geometrical shape that I can't even remember the name of. Old age ain't for sissies.

Anyway, since HT has always been the go-to place for obscure knowledge, I was hoping someone here might be able to remember enough of what I've dis-remembered to get me headed in the right direction. Does anyone know the name of this shape (and dare I ask, the formula for it)?

[Shoden]

Maybe try hyperbolic or vortex funnel, along with "geometric shape" to narrow down the results. I'm far from a math expert, but I Googled those terms and found some interesting reading.

[carasel]

Is this what you need ? The radius sides will change things a little. Where the top is flat. Figure the dimensions for the part not there. Radius and height. Work your formula. Then subtract from your first total. You'll be close.

[wy_white_wolf]

At first I thought trunciated cone but they have straight sides. The curved sides would put it into the barrel shapes. Not sure what you call a barrel with top & bottom radii different.

Could try using the formula for the volume of a barrel and substitute the radius part of the trunciated cone volume formula for the top & bootom radii.

WWW

[DaleK]

You never said what you wanted to find. Volume, surface area?

[TnAndy]

Yep...what Dale said.....

[deaconjim]

I'm looking for the equation to plot the shape of the cone. For example, the equation for a vertical parabola is:

y=a(x-h)2+k

If I can find the name of the shape, I can find the formula.

[Cabin Fever]

Assuming you want the volume, what I would do is visually "slice" it into several trucated cones. Yes, the sides are curved, but the answer will be close, especially if you slice it into many truncatec cones. The more slices you cut the shape into, the closer you'll get to the acutal answer.

[Cabin Fever]

I have no idea how one plots the shape of a three-dimenisional object. My limit is two-dimenisonal.

[DaleK]

I'm thinking hyperbolic cone

[baleksivich]

This might help you out.

http://tutorial.math.lamar.edu/Class...cSurfaces.aspx

[Explorer]

Originally Posted by DaleK

I'm thinking hyperbolic cone

Agree. It's shape looks like a hyperbolic natural draft cooling tower used in modern power plants.

[deaconjim]

Baleksivich, thank you. The shape is a hyperboloid, now I just need to fill in the blanks of the equation.

[deaconjim]

Originally Posted by Cabin Fever

I have no idea how one plots the shape of a three-dimenisional object. My limit is two-dimenisonal.

I'm not real good at it either, and it has been a couple of decades since I've even tried.

[baleksivich]

glad I could help. Good luck.