1)An air traffic controller spots two airplanes at the same altitude converging to point A as they fly at right angles to each other. One airplane is 180 miles from point A and has a speed of 720 miles per hour. The other is 290 miles from point A and has a speed of 1160 miles per hour.
At what rate is the distance between the two planes changing?
2)An accident at an oil drilling platform is causing a circular oil slick. The slick is 0.13 feet thick, and when its radius is 1100 feet, the radius is increasing at a rate of 0.1 feet per minute.