Pedro  P. Ortega Palencia, Ruben  Dario Ortiz, J. Guadalupe  Reyes Victoria, 
    A Simple Expression for the Center of Mass of a System of Particles in a
Two-Dimensional Space with Constant Positive Curvature,
    Journal of Engineering and Applied Sciences,
    Volume 14,Issue 24,
    2019,
    Pages 9603-9607,
    ISSN 1816-949x,
    jeasci.2019.9603.9607,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2019.9603.9607)
    Abstract: In this research is given a simple expression for the center of mass of a system of material points in
a two-dimensional surface of Gaussian constant positive curvature. Using basic techniques of geometry, an
expression in intrinsic coordinates is obtained and it is showed how this extend the definition for the Euclidean
case. The argument is constructive and also serves for defining center of mass of a system of particles on the
one-dimensional Sphere S<sup>1</sup><sub>R</sub>.
    Keywords: Center of masses;conformal metric;spherical rule of the lever;geodesic;Euclidean case;one-dimensional sphere