AP EAMCET Engineering 20 Apr 2019 Shift 1 Paper

Two particles P and Q each of mass 3m lie at rest oil the X-axis at points (-a. 0) and (+a.0) respectively. A third particle R of mass 2m initially at the origin moves towards particle Q. If all the collisions of the system of 3 particles are elastic and head-on. the total number of collisions in the system is