The Leaning Tower of Pisa is 55 m tall and about 7.01 m in diameter. The top is displaced sideways by 4.49 m from where it would be if the tower were vertical. The tower is in stable equilibrium right now, but how much farther can it lean before it becomes unstable? Assume the tower is of uniform composition.

 

how do i approach this?

I would assume that you need to use the principle of "rigid body equilibrium". I didn't learn it yet as I will probably learn it next semester. Sorry if I can't be any helpful than this.

Find the center of mass. when that is above the normal from the ground from on the corerns then it'll fall onto it's side.

 

This is massively simplified as it has foundations etc which are just being ignored.

Depends on the location of its center of mass.

When a plumb line from its center of mass falls outside the base footprint, it will fall... unless it is glued to the soil.

Miguel