1. A woman standinh on a cliff is watching a motorboat through a telescope as the boat approachs the shoreline directly below. If the telescop is 100 feet above the water level and if the boat is approaching at 30 feet per seconds, at what rate is the angle of the telescop changing when the boat is 200 feet from the shore?
2. Water is pouring into a conical tank at the rate of 8 cubic feet per minute. If the height of the tank is 10 feet and the radius of its circular opening is 7 feet, how fast is the water level rising when the water is 4 feet deep?
3. A small balloon is released at a point 150 feet away from an observer, who is on level ground. If the balloon goes straight up at a rate of 5 feet per second, how fast is the distance from the observer to the balloon increasing when the balloon is 10 feet high?