Decomposition of "Meeting" Problems into Multiple Systems 
One common type of problem that often involves the One-Dimensional Motion with Constant Acceleration model has the goal of determining where two objects meet. Because this model can only describe the motion of a single particle, solving for the point at which two objects meet requires that the problem be approached by considering the two objects to be separate systems governed by separate models (or separate realizations of the same model). Finding the meeting point requires that appropriate constraints be applied to each system in order to ensure that their relative positions be accurate at the initial time and that they be equal at the meeting time.
Speed Trap (Police car with constant acceleration must catch speeder with constant velocity. )