Question

One ship is approaching a port from the east, traveling west at 15 miles per hour, and is presently 3 miles east of the port. A second ship has already left the port, traveling to the north at 10 miles per hour, and is presently 4 miles north of the port. At this instant, what is the rate of change of the distance between two ships? Are they getting closer or further apart?

Answer 1

The rate of change of distance between the two ships is 1 miles per hour.

The negative sign implies that the distance between the two ships is decreasing, i.e, they are getting closer.