Decomposition of "Meeting" Problems into Multiple Systems 
One common type of problem that often involves the One-Dimensional Motion with Constant Velocity 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 model be applied twice considering the two objects to be separate systems. 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.
Where Do We Meet? (Two people moving in one dimension with constant speed are destined to meet – but where?)