Thursday, September 9, 2010
9/8/2010 In Class Challenge
In this challenge the class was split up into groups of three people and had to build the tallest structure, using a piece of tape and five pieces of newspaper. The rules were that the structure had to stand up by itself and be portable. The tallest structure built was around 160 cm.
My group first tried to make a structure out of rolling the pieces of newspaper into equal cylinders and stacking them on top of each other. That did not work however, because firstly, the pieces were very not stable, and the structure was too heavy at the top for the base to support it. We rolled the paper at the top, adding unnecessary weight. In addition we did not use the tape very reasonably, because in the end we were left with parts of the structure's top that were not stuck together properly and kept breaking. We set two pieces of newspaper aside for the base which we rolled into a ball and stuck the tower of our structure in. Because we could not stick the base to the ground our structure ended up falling.
I noticed that most of the successful structures in the class (i.e. the tall and stable ones) had a tripod base.
If I had to redo the challenge i would put less weight on top of the structure (by rolling half a piece of paper instead of a full one), and make the base wider.
Physics of a Tall Structure
- wide base
- use of triangles
- heavy base
- adding more support points
- taper the structure by making the top less heavy and skinnier
- a lower center of gravity makes it easier for the building to balance
The center of gravity(often called the center of mass) is the mean location of the mass in a structure. In order to stabilize a structure, engineers need to locate the center of gravity of a structure, and also distribute the mass of the structure evenly around it. The force of gravity acts on everything (i.e. all parts of the structure) so if the weight of the structure is distributed around it evenly, the structure will be stable.
For structures built outside the foundation on which they are built must be stable. The foundation must not be very moist. Also if the type of foundation is not taken into account, the structures may get cracks in their walls and the foundation.