What is it that is actually causing the gravity to make things fall off the end? A flat surface is fairly unstable, the other forces it would be flexible and move around. More from Tech Stuart ...
Faces - A face is a flat surface on a 3D shape. For example a cube has 6 faces. Edges - An edge is where two faces meet. For example a cube has 12 edges. Vertices - A vertex is a corner where ...