# Thread: Related Rates problem elp

1. ## Related Rates problem elp

Ship A is sailing due south 16mph. At the same time, a second ship B, 32miles south of A, is sailing due east at 12mph. At what rate are they approaching or separating at the end of the hour. At what rate are they approaching or separating at the end of two hours? when do they cease to approach each other an how far apart are they at that instant?

i got 5.6 appoachin at 1 and 12 seperating at 2 doesnt make sense to me and i have no clue how to do the last part i also want to see how to get d(hypotouse)/dt help please

2. Originally Posted by JM0C
Ship A is sailing due south 16mph. At the same time, a second ship B, 32miles south of A, is sailing due east at 12mph. At what rate are they approaching or separating at the end of the hour. At what rate are they approaching or separating at the end of two hours? when do they cease to approach each other an how far apart are they at that instant?

i got 5.6 appoachin at 1 and 12 seperating at 2 doesnt make sense to me and i have no clue how to do the last part i also want to see how to get d(hypotouse)/dt help please
Excellent! I got exactly your answers for the first two parts.

I presume that, to do that, you found a formula for the distance between the two boats at time t and differentiated it. Okay, set the derivative of distance equal to 0 (the cease to approach each other when that derivative is 0) and solve for t. (That turns out to be very easy.) Use that value of t to determine where the two boats are at that time and then find the distance between them.