Will+Dang

__**How Does A Leaning Tower Stay Standing?**__

//The Leaning Tower of Pisa is able to stand, and still stands today due to mainly three important physics concepts. Gravity, Balance, and Center of Mass are all qualities that must be considered when one ponders about this mysterious question.//

**__Background__** The Leaning Tower of Pisa's lean actually exists as result of the tower's weak foundation from the unstable subsoil that it was built upon. The historical architects of this wonder did not take into consideration that the ground on which the tower was built upon was not strong enough to support such a large structure. During the construction, the lean had already been noticed by the builders. More specifically, the tower started to lean upon the construction of the third level.

__**The Leaning Tower and Physics**__ After the construction had completed, the tower has continuously increased its lean every year, which has altered the balance initially established with the building, the shift of the center of mass towards the right, and the effect of gravity's pull on the object. Through the work of historians, mathematicians, architects, and engineers, many attempts have been made to stabilize the tower so that it does not eventually topple over and collapse. The tower is now able to stand at a tilted angle without toppling over because steel cables have been used to shift the tower's center of mass back to its base of support, which is located in the center of the tower. Because the center of mass is actually more towards the center now, it is much easier for the tower to maintain its balance and not topple over. Also some of the subsoil had been drilled and removed in order to establish a stronger foundation for the tower to reside in. With a stronger foundation and a shift in the center of mass, a more stable state of balance has been achieved. Furthermore, gravity also helps to pull the tower down to the ground towards the center of mass, which also helps to keep the leaning tower from toppling over. The use of the steel cables and the drilling of the ground to create a stronger base largely helped to bring the tower center of mass approximately 20 inches to the left, which has greatly affected the tower's ability to stand.



Throughout the years, preservers of this ancient wonder have been successful in effectively maintaining the tower's center of mass, its balance, and gravity's pull on its structure in order to keep the tower standing for many years to come. Without the maintenance, the collapsing of the tower pictured above would have happened very soon.

__**Physics Topic Categories**__ - Balance - Center of Mass
 * -** Gravity

**__References__** [] [|http://schools.wikia.com/wiki/Center_of_Mass#Leaning_Tower_of_Pisa] []