7 The masses of two particles \(A\) and \(B\) are \(m\) and \(2 m\) respectively. They are moving towards each other on a smooth horizontal table. Just before they collide their speeds are \(u\) and \(2 u\) respectively. After the collision the kinetic energy of \(A\) is 8 times the kinetic energy of \(B\). Find the coefficient of restitution between \(A\) and \(B\). \section*{END OF QUESTION PAPER}