A problem regarding buoyancy of simple figures suitable for Problem-Based Learning

Abstract

A machine can make three-dimensional figures that can float on different types of liquids, using for each figure always the same quantity of mass. The machine had already made spheres when the engineers intended to design other figures that reached the same depth below the surface. They tested with cubes and realized that regardless of the liquid on which figures floated, spheres always reached a greater depth than cubes. Could their problem be solved using cones?