- Two particles, \(P\) and \(Q\), have masses \(m\) and \(e m\) respectively. The particles are moving on a smooth horizontal plane in the same direction along the same straight line when they collide directly. The coefficient of restitution between \(P\) and \(Q\) is \(e\), where \(0 < e < 1\)
Immediately before the collision the speed of \(P\) is \(u\) and the speed of \(Q\) is \(e u\).
- Show that the speed of \(Q\) immediately after the collision is \(u\).
- Show that the direction of motion of \(P\) is unchanged by the collision.
The magnitude of the impulse on \(Q\) in the collision is \(\frac { 2 } { 9 } m u\)
- Find the possible values of \(e\).