6. A particle \(A\) of mass \(2 m\) is moving with speed \(2 u\) on a smooth horizontal table. The particle collides directly with a particle \(B\) of mass \(4 m\) moving with speed \(u\) in the same direction as \(A\). The coefficient of restitution between \(A\) and \(B\) is \(\frac { 1 } { 2 }\).

1. Show that the speed of \(B\) after the collision is \(\frac { 3 } { 2 } u\).
2. Find the speed of \(A\) after the collision. Subsequently \(B\) collides directly with a particle \(C\) of mass \(m\) which is at rest on the table. The coefficient of restitution between \(B\) and \(C\) is \(e\). Given that there are no further collisions,
3. find the range of possible values for \(e\).
   (8)