Three equal masses of $m$ are fixed at the vertices of an equilateral triangle ABC of side $L$. What

Question

Three equal masses of $m$ are fixed at the vertices of an equilateral triangle ABC of side $L$. What is the gravitational force acting on a mass $2m$ placed at the centroid G of the triangle?

Professor PC Thomas Classes · Answer

Due to the symmetry of the equilateral triangle, the gravitational forces exerted by the three masses at the vertices on the mass at the centroid are equal in magnitude and are separated by $120^\circ$. Their vector sum is zero.