l The conical watering pail with height 0.45 m and radius 0.15 in has a grid of holes' Water ows out through the holes at a rate of \\ kA m3/min, where k is a constant and A is the surface area of the part of the cone in contact with the water. This surface area is \\ A = nn/ I12 4- r?- and the volume is V = %m'2 h. Calculate the rate % at which the water level changes at h = 0.33 m, assuming \\ that k = 0.2l mlmin