Sand falls from a conveyor belt at a rate of 20 meters cubed per minute onto the top of a conical pile. The height of the pile is always three-eights of the base diameter.

Question

How fast (in m/min) is the radius changing when the pile is 6 meters high?

Answer 1

Hi Shoba,

You're dealing with a conical shape. The volume of a cone is

V = (1/3)*π*r²*h.

I show you the rest of the steps in the video, if you'd like to watch.

Cheers.