Three identical metal balls each of radius `r` are placed touching each other on a horizontal surface such that an equilateral triangle is formed, when the center of three balls are joined. The center of mass of system is located at the

Options

A. Horizontal surface
B. Centre of one of the balls
C. Line jointing centres of any two balls
D. Point of intersection of the medians

Answer

C

Explanation

Centre of mass of the system at the centroid (i.e. intersection of medians).