calculus
posted by Ash .
Gravel is being dumped from a conveyor belt at a rate of 10 cubic feet per minute. It forms a pile in the shape of a right circular cone whose base diameter and height are always equal to each other. How fast is the height of the pile increasing when the pile is 20 feet high?

v=1/3*pi*r^2h r=2/h
V=1/3*pi*(h/2)^2*h
=1/3*pi*h^2/4*h
=1/12*pi*h^3
V'=10ft^3/min
h=20ft
V'=1/12*pi*3h^2*h'
10=1/12*pi*3(20)^2*h'
solve for h'