Right Circular Conoid
The right circular conoid is the right conoid having a circle as its directrix.
A right circular conoid is also known as the Wallis conocuneus or cono-cuneus. Wallis
(1684) described the corresponding solid as the "shipwright's
circular wedge." A right circular conoid with base in the -plane, narrowing along the positive
-axis, and with radius
and height
has parametric equations
|
(1)
| |||
|
(2)
| |||
|
(3)
|
for
and
.
Its cartesian equation is
|
(4)
|
with
and
.
The volume of the solid enclosed by capping the bottom is given by
|
(5)
| |||
|
(6)
|
At ,
where
is the Laplace limit, this is also the volume
bounded by the critical catenoid spanning two
equal coaxial circles of radius
, although the interior cross
sections of the two solids are different (Anderson
2026).
The surface area (of the lateral portion only, thus excluding the base circle) is given by
|
(7)
|
This is more difficult to get in closed form, but for the case ,
the integral can be reduced to
|
(8)
| |||
|
(9)
| |||
|
(10)
|
(OEIS A371923).
See also
Cone, Conoid, Critical Catenoid, Right ConoidExplore with Wolfram|Alpha
References
Anderson, T. "The Volume of the Critical Catenoid." Math. Intelligencer, 2026. https://doi.org/10.1007/s00283-026-10551-0.Wallis, J. Cono-Cuneus: or, The Shipwright's Circular Wedge. London, England: J. Playford for R. Davis, 1684. https://archive.org/details/bim_early-english-books-1641-1700_cono-cuneus-or-the-shi_wallis-john_1684.Sloane, N. J. A. Sequence A371923 in "The On-Line Encyclopedia of Integer Sequences."Referenced on Wolfram|Alpha
Right Circular ConoidCite this as:
Weisstein, Eric W. "Right Circular Conoid." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/RightCircularConoid.html