The Leaning Tower of Pisa is 55 m tall and about 7.7 m in radius. The top is 4.5 m off center. Is the tower in stable equilibrium? If so, how much farther can it lean before it becomes unstable? Assume the tower is of uniform composition.
Source: Giancoli, Douglas C., Physics: Principles with Applications, 7th Edition, 2014.
The tower is in stable equilibrium. If the top leans 9.8m more, it will be in unstable equilibrium and eventually fall when the wind blows or if there's an earthquake.