relative motion. I've not a clue. OK I really need help with this problem. I don't even know where to start. If someone could just point me in the right direction, I'd appreciate it. I just need to know where to start. thanks. Ships A and B leave port together. For the next 2 hrs, ship A travels at 20 mph in a direction 30 degrees west of north while ship B travels 20 degrees east of north at 25 mph. What is the distance between the 2 ships two hours after they depart?