Cones and Water, LAWL.Calculus Level pending
A cone shaped water tank starts off full. The radius of the cone is 5 cm and the height is 20 cm. If the water is flowing out of the vertex at a rate of 4 cm^3 per minute, then how fast is the depth of the water decreasing when the height is 2 cm?
Note: Put the answer in decimal form to the nearest tenth.