- Two particles, \(A\) and \(B\), have masses \(3 m\) and \(4 m\) respectively. The particles are moving in the same direction along the same straight line on a smooth horizontal surface when they collide directly. Immediately before the collision the speed of \(A\) is \(2 u\) and the speed of \(B\) is \(u\).
The coefficient of restitution between \(A\) and \(B\) is \(e\).
- Show that the direction of motion of each of the particles is unchanged by the collision.
(8)
After the collision with \(A\), particle \(B\) collides directly with a third particle, \(C\), of mass \(2 m\), which is at rest on the surface.
The coefficient of restitution between \(B\) and \(C\) is also \(e\). - Show that there will be a second collision between \(A\) and \(B\).