Center Of Mass - Leaning Tower On Incline Plane
To demonstrate that an object is in stable equilibrium when its center of mass is above its base.
Leaning tower and inclined plane, as photographed.
On a horizontal surface, the addition of the tower top shifts the center of mass, causing the configuration to change from stable (without top) to unstable (with top). When the tower is placed on the incline, even with the top, the configuration is still stable because the center of mass is still over the base.