A circle has a radius that is increasing at a rate of 13/π feet per hour. What is the rate of change of the area of the circle when the radius is 7 feet?

Adolphin is swimming with her friend. the dolphin jumps to a height of 4.54.54, point, 5 meters above the surface of the water as her friend swims 9.89.89, point, 8 meters directly below her. what is the position of the dolphin's friend relative to the surface of the water? meters