# Calculus: free body diagram--PLZ HELP!=)

posted by
**lizzy**
.

Grain is being poured through a chute at a rate of 8 cubic feet per minute and forms a conical pile. The radius of the bottom of the pile is always half of the heightof the pile. How fast is the circumference of the base increasing when the pile is 10 feet high?

..I keep getting 2 different answers: 8/25pi and 10/9pi. Please HELPPPPPPPP!! LOL =)