Two friends, Ankit and Bharat, each weighing 40 kg, sit at a separation of d on a frictionless platform. Ankit rolls a 4 kg ball along the platform towards Bharat, who catches it. Bharat subsequently rolls the ball back to Ankit, who catches it. This back-and-forth motion of the ball between the two friends continues. The ball travels at a constant speed of 5 m/s relative to the platform. Where is the centre of mass

Step-by-step solution

Since the platform is frictionless, there is no net external force acting on the system consisting of Ankit, Bharat, and the ball in the horizontal direction. Therefore, the center of mass of the system remains stationary throughout the motion, regardless of the internal movements. Let the initial position of Ankit be at the origin, x_A = 0 . The initial position of Bharat is x_B = d . The ball is initially with Ankit, so its initial position is x_ ball = 0 . The given masses are m_A = 40 kg, m_B = 40 kg, and m_ ba