1. The problem statement, all variables and given/known data Three perfectly elastic particles A, B, C with masses 4 kg, 2 kg, 3 kg respectively, lie at rest in a straight line on a smooth horizontal table. Particle A is projected towards B with speed 15 m/s and after A has collided with B, B collides with C. Find the velocities of the particles after the second collision and state whether there will be a third collision. 2. Relevant equations v1-v2= -e (u1-u2) Momentum before collision and momentim after collision equations using the principle of conservation of momentum. 3. The attempt at a solution Well I formed the equations using the equations stated above. Should I include the momentum of all 3 before collision together and do the same for after or should I do it separately between A and B first and then B and C? If I do it for all 3 together then how will this equation v1-v2= -e (u1-u2) change? e=1 for a perfectly elastic collision.