Three identical particles, each of mass m, are located in space at the vertices of an equilateral triangle of side length a. They are revolving in a circular orbital under mutual ravitational attraction. Find the speed of each particle. Find the acceleration of the centre of mass of a system comprising of any two particles. Assume that one of the particles suddenly loses its ability to exert gravitational force. Find the velocity of the centre of mass of the system of other two particles after this.