At noon, ship A is 100 km west of ship B. Ship A is sailing south at 25 km/h and ship B is sailing north at 35 km/h. How fast is the distance between the ships changing at 4:00 PM

Explanation:

The ship A is 100 Km west of ship B. The speeds of the ship A and B are 25 Km/hour and 35 Km/hour and the distance between the two ships is 100 Km.

Note: Refer the fig attached

At t hours, the ship A moves at a distance 25 t Km and the ship B move at a distance of 35 t.

The total distance travelled by ship A and ship B is

Note: Refer the 2 image

From the figure, it is observed that the total distance travelled by the two ships is,

Differentiate on both sides with respect to t .

At 4 pm (Plug t =4), the speed in which the distance between the two ships is,