Three equal masses of ‘m’ kg are fixed at the vertices of an equilateral triangle ABC. The force acting on mass ‘2m’ kg placed at the centroid of  triangle is

Force of attraction between two masses=GMmr2;universal gravitation constant=G; mass=m; distance=r; F1=F2=F3=Gm2mAD2 ∴AD=CD=BD three equal forces of same magnitude acting on a point with θ=1200 angle  between any two adjacent forces lying in a plane then resultant force= 0