At noon, ship A is 130 km west of ship B. Ship A is sailing east at 25 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?

answer = 12.87 km/h

Step-by-step explanation:

Given

Ship A is sailing east at 25 km/h =

ship B is sailing north at 20 km/h =

here x and y are the  sailing at t = 4 : 00 pm for ship A and B respectively

so we get x = 4 ×25 =100 km/h

                 y = 4× 20 = 80 km/h

let z is the distance between the ships, we need to find at t = 4 hr

At noon, ship A is 130 km west of ship B (12:00 pm)

so equation will be

derivative first equation w . r. to t we get