Shortest route to intersection

Answer 1

There are an infinite number of possibilities. Consider a concentric series of circles from the points R and T, representing the distance each could travel at increasing times. Where the circles intersect is the point of collision, a vector between the point of collision and T is where T should have been aimed at for that particular instant. If you are looking for the shortest path, you need to get the normal to R's path and fire T at the appropriate time by calculating the time it takes for T to traverse this distance so it will arrive at the same time as R.