1. The problem statement, all variables and given/known data Two points P and Q have position vectors in a reference frame that are given by rOP = 50ti and rOQ = 40i - 20tj meters. Find the minimum distance between P and Q and the time at which this occurs. 2. Relevant equations 3. The attempt at a solution I suppose I take the magnitude of each vector, but then what? They both share the same origin, how do i manipulate it so that they give me the PQ length?