Sand is being poured into an open right circular cone container, as shown in the figure. The height of the container is 8 cm, and the diameter of the opening is 8 cm. Sand is being poured in so that its depth his changing at a constant rate 4 of cm/min. 10 8 cm 8 cm = 1 {rrh.) (Note: The volume of a cone of height h and radius r is given by V= Part A: Find the volume V of sand in the container when h = 4 cm. Indicate units of measure. (10 points) Part B: Find the rate of change of the volume of sand in the container, with respect to time, when h = 4 cm. Indicate units of measure. (20 points)