Two identical small balls are interconnected with a light and inextensible thread having length L. The system is on a smooth horizontal table with the thread just taut. Each ball is imparted a velocity `v`, one towards the other ball and the other in a direction that is perpendicular to the velocity given to the first ball.
(a) After how much time the thread will become taut again?
(b) Calculate the kinetic energy of the system after the string gets taut.
