1. The problem statement, all variables and given/known data There are two moving objects. The velocity of the first object, u, is constant. The second object maintains a constant velocity, v, perpendicular to u. The distance between the two objects is x. What is the second object's acceleration, a, in that moment? 3. The attempt at a solution I'm unsure of how to really begin and if I'm on the right track but since the acceleration is perpendicular to u, there would be a centripetal force, because when acceleration is perpendicular to velocity there is circular motion. Would a=v2/r show the relationship? Edit: Sorry about the typo in the title. It should say "two"