At noon, ship A is 170 km west of ship B. Ship A is sailing east at 40 km/h and ship B is sailing north at 20 km/h. How fast is the distance between the ships changing at 4:00 PM?
40 times 4hours=160 km east for ship A Ship B goes 80 km north. 170-160=10 10^2=100 80^2=6400 6400+100=6500 square root 6500 and you get the distance they are away from each other at four o'clock which is about 80.622 km away.
