Physics Challenge

The physics of tall structures:
  
     When building a tall structure, you need to consider many factors in order to ensure the structure is stable enough and will not fall or tip over at the smallest gust of wind. For this challenge, groups were required to build the tallest free-standing structure they could using rolls of newspaper.  Although sadly, I was not here for the challenge and did not get to participate, I learned a lot about the methods that my fellow classmates (and famous architects!) incorporated into their designs.
     For instance,  many groups used a heavy base made up of legs in a triangular or square based pyramid. They used this heavy base to support a very tall, thin, but light tower that got thinner as it progressed higher. This seemed to work the best for many of the groups who made sure to properly proportion the thickness of their tower.
     In real life, architects have to consider many more factors when designing a tall structure. For instance, weather conditions (such as the wind), location, area, and so on.  But what generally remained the same between the class ideas and an architect's ideas was that the base had to be heavy and strong enough to support a lighter upper mass. However, in real life, many architects tend to use more complex shapes and designs to successfully stabilize a structure while maintaining an aesthetically pleasing look.


What makes a tall structure stable?

     The most important thing when designing a tall structure is that is able to hold itself up.  Therefore, tall structures must be carefully planned out, from the base up.  Many different tall structures use different mechanisms and designs to remain stable.  For instance, the CN Tower in Toronto, Canada, has a massive underground foundation, that supports a thin, rising, and relatively light shaft that got progressively thinner. For the Burj Khalifa in Dubai, a more complicated "buttressed core" design (a hexagonal core reinforced by three buttresses arranged in a Y-shaped) along with another huge base, were used.

What is the centre of gravity?

   The centre of gravity is a geometric property of any object that every architect must consider when designing a building.  By definition, the centre of gravity is the average location of an object's weight, or in other words, the mean location of the gravitational forces acting on the object. Note*: the centre of gravity does not always have to be in the exact centre of an object, especially if the upper and lower halves are not perfectly symmetrical.