Suppose you are a sheet-metal worker and are tasked with designing a cylindrical storage container made from your highest quality sheet metal. You are told the container needs to be closed on the bottom, but open on top, and have a total volume of 30m^3. Because the top-of-the-line metal is the most expensive, you do not want to use any more than is absolutely necessary, in order to avoid wasteful spending. Therefore determine the dimensions of the container that will minimize the amount of material needed to construct the container.