1. The problem statement, all variables and given/known data Sand falls from a conveyor belt at the rate of 10 m^3/min onto the top of a conical pile. The height of the pile is always three-eighths of the base diameter. How fast are the a) height and b) radius changing when the pile is 4m high? 2. Relevant equations h = 3/8 * 2r 3. The attempt at a solution I'm not sure where to start. I just need a small hint.