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 h is changing at a constant rate of 2 divided by 10 cm/min.

open right circular cone with a diameter of 8 cm and a height of 8 cm partially filled up, showing a radius of r and a height of h

(Note: The volume of a cone of height h and radius r is given by V is equal to one over three times pi times r squared times h period)

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)