2. (3 points) Sand flows from the top half of a conical hourglass to the bottom half. The top half has the shape of the graph y = (x| rotated about the y-axis. When the top half contains sand to a depth of h units, it flows out through a hole in the bottom half at a rate (volume/time) proportional to h, with constant of proportionality 3. Show that the sand level falls at a constant rate