A353771 Decimal expansion of the gravitational acceleration generated at the center of a face by unit-mass regular tetrahedron with edge length 2 in units where the gravitational constant is G = 1.

2, 5, 6, 3, 3, 1, 1, 8, 1, 6, 1, 4, 3, 6, 4, 9, 4, 6, 6, 8, 8, 2, 2, 9, 3, 9, 5, 7, 5, 4, 8, 4, 0, 7, 9, 5, 1, 8, 3, 4, 5, 8, 5, 1, 1, 7, 5, 9, 1, 1, 8, 4, 4, 9, 6, 7, 7, 0, 3, 9, 4, 4, 9, 2, 4, 6, 4, 9, 0, 1, 6, 3, 8, 2, 5, 4, 0, 1, 8, 9, 5, 0, 9, 0, 7, 3, 0, 4, 6, 7, 2, 2, 8, 6, 8, 0, 9, 4, 5, 2, 9, 5, 2, 0, 7

Offset: 1

Author

Amiram Eldar, May 07 2022

Keywords

• nonn
• cons

Comments

The absolute value of the gravitational attraction force between a homogeneous regular tetrahedron with mass M and edge length 2*s and a test particle with mass m located at the tetrahedron's center of face is c*G*M*m/s^2, where G is the gravitational constant (A070058) and c is this constant.

The centers of the faces are the positions where the gravitational field that is generated by the tetrahedron attains its maximum absolute value.

Examples

			2.56331181614364946688229395754840795183458511759118...
		

Links

• Murray S. Klamkin, Extreme Gravitational Attraction, Problem 92-5, SIAM Review, Vol. 34, No. 1 (1992), pp. 120-121; Solution, by Carl C. Grosjean, ibid., Vol. 38, No. 3 (1996), pp. 515-520.
• Eric Weisstein's World of Physics, Polyhedron Gravitational Force.
• Eric Weisstein's World of Physics, Tetrahedron Gravitational Force.

Crossrefs

Cf. A070058, A353769, A353770, A353772, A353773.

Programs

Mathematica

RealDigits[2*Pi/(3*Sqrt[3]) + Sqrt[6]*Log[Sqrt[3] + 2] - 2*Sqrt[6]*Log[Sqrt[3] + Sqrt[2]]/3, 10, 100][[1]]

Formula

Equals 2*Pi/(3*sqrt(3)) + sqrt(6)*log(sqrt(3) + 2) - 2*sqrt(6)*log(sqrt(3) + sqrt(2))/3.