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Kiss Surface


KissSurface

The kiss surface is the quintic surface of revolution given by the equation

 x^2+y^2=(1-z)z^4
(1)

that is closely related to the ding-dong surface. It is so named because the shape of the lower portion resembles that of a Hershey's Chocolate Kiss.

It can be represented parametrically as

x(u,v)=av^2sqrt((1-v)/2)cosu
(2)
y(u,v)=av^2sqrt((1-v)/2)sinu
(3)
z(u,v)=av.
(4)

The coefficients of the first fundamental form are

E=1/2a^2(1-v)v^4
(5)
F=0
(6)
G=(a^2(8-8v+16v^2-40v^3+25v^4))/(8(v-1))
(7)

and of the second fundamental form are

e=(2a(v-1)v^2)/(sqrt(8-8v+16v^2-40v^3+25v^4))
(8)
f=0
(9)
g=(a(8-24v+15v^2))/(2(1-v)sqrt(8-8v+16v^2-40v^3+25v^4)).
(10)

The Gaussian and mean curvatures are given by

K=-(16(8-24v+15v^2))/(a^2v^2(8-8v+16v^2-40v^3+25v^4)^2)
(11)
H=-(4(4-4v+4v^2-8v^3+5v^4))/(av^2(8-8v+16v^2-40v^3+25v^4)^(3/2)).
(12)

The Gaussian curvature can be given implicitly by

 K(x,y,z)=(16(8-24z+15z^2))/(z^2(8-8z+16z^2-40z^3+25z^4)^2).
(13)

The surface area and volume enclosed of the top teardrop are given by

S=0.755023...a^2
(14)
V=1/(60)pia^3.
(15)

Its centroid is at (0,0,5/7a) and the moment of inertia tensor is

 I=[(251)/(462)Ma^2 0 0; 0 (251)/(462)M 0; 0 0 1/(66)Ma^2]
(16)

for a solid kiss with uniform density and mass M.


See also

Ding-Dong Surface, Pear-Shaped Curve, Quintic Surface, Teardrop Curve

Explore with Wolfram|Alpha

References

Nordstrand, T. "Surfaces." http://jalape.no/math/surfaces.

Cite this as:

Weisstein, Eric W. "Kiss Surface." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/KissSurface.html

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