Edexcel M2 2021 June — Question 8

Exam BoardEdexcel
ModuleM2 (Mechanics 2)
Year2021
SessionJune
TopicMomentum and Collisions 1

  1. Particles \(A , B\) and \(C\), of masses \(2 m , m\) and \(3 m\) respectively, lie at rest in a straight line on a smooth horizontal plane with \(B\) between \(A\) and \(C\). Particle \(A\) is projected towards particle \(B\) with speed \(2 u\) and collides directly with \(B\).
The coefficient of restitution between each pair of particles is \(e\).
    1. Show that the speed of \(B\) immediately after the collision with \(A\) is \(\frac { 4 } { 3 } u ( 1 + e )\)
    2. Find the speed of \(A\) immediately after the collision with \(B\). At the instant when \(A\) collides with \(B\), particle \(C\) is projected with speed \(u\) towards \(B\) so that \(B\) and \(C\) collide directly.
  1. Show that there will be a second collision between \(A\) and \(B\).
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