Estimating gravimetric effects for ordinary bodies

The main topic of this article is a discussion about the best way to show students that the proportionality of mass and weight, strictly true for point-like particles, is an excellent approximation for objects of "normal" size. The usual way of addressing this issue, although very simple, is not entirely satisfactory. Our approach considers first and second order, coordinate dependent, gravimetric effects, connected to the internal geometry of objects; these effects, extremely small, are estimated through examples.