# Tough kinematics question

2 point particles, A and B, are a distance d apart in a vacuum.

from time t=0 onwards, A has a constant nonzero velocity with magnitude v and a direction perpendicular to AoBo, where Ao and Bo are the initial positions of A and B........

I think"perpendicular to AoBo" is correct not "perpendicular to AB"
So A moves with a constant velocity (same direction).
B moves towards A and its direction will keep changing more and more towards that of A. Their relative velocity will tend towards zero. Their separation will tend to a constant value.

You will need integral calculus to solve this
You will see a similar problem in the first few pages of Irodv "Physics Problems"

yes, the answer is d/2. actually i was looking for a simple method to solve the problem which didn't involve direct integration; but thanks, arcnets, for your help - it's useful to know how to solve general pursuit curve problems. :)