A tank of water in the shape of an inverted cone (i.e. circular base on top) is leaking water a constant rage of 1 ft3/min. The base radius of the tank is 5 ft and the height of the tank is 14 ft. (a) At what rate is the depth of the water in the tank changing when the depth of the water is 6 ft? (b) At what rate is the radius of the top of the water in the tank changing when the depth of the water is 6 ft?