1. The problem statement, all variables and given/known data At noon, ship A is 150km west of ship B. Ship A is sailing east at 35km/h and ship B is sailing north at 25km/h. HOw fast is the distance between the ships changing at 4:00pm. 2. Relevant equations ?? 3. The attempt at a solution I was able to draw a picture of the problem, but I don't know where to go from there, and I also understand that I am trying to solve for dz/dt, but I have no clue how to do that, please help :).