Forces
Hello bloggers of the internet! Welcome to the epilogue of our bridge project's blog! You thought the blog was over? Well then this is a good surprise, isn't it?! Today I will be explaining the basic physics, more specifically the forces, behind this bridge and how it was SO STRONG. Starting off, let me simply give a brief and simple definition of forces. A force is an action that causes an object to move, and when all the forces on an object are equal, that is called equilibrium, or at rest. First, let's start off explaining the forces at one of the triangle gussets, specifically, the one on the left(although both will have the same forces acting on them).
The area we will now focus on.
First, let me show a picture of all forces acting on this part of the triangle.
OK! With this force diagram, let me explain every force shown. To start it off, we can begin with Fn. This is called the Normal Force. Basically, this is the force acting on an object from the surface it's resting on so that gravity doesn't PULL IT STRAIGHT INTO THE CENTER OF THE EARTH AND DESTROY ITS VERY SOUL. This force is equal with gravity most of the time when an object is resting on a surface. Now, let's move on to the force labeled Fc. This is called the Compression Force. When we added the weight to the bridge to test it, the tubes of the bridge compressed making them smaller in length, although a very minuscule amount. When these tubes are compressed, they actually have a force acting on the surface to keep the bridge from collapsing down, thus making the force in the tubes stronger to sustain the bridge. Finally, I shall explain the Ft force. After the weight was added to the bridge, the thin strips we constructed were stretched which caused them to create a stronger force that was equal to the compression force so that the bridge will stay in equilibrium. Without the tension, the bridge would collapse into itself, and without the compression, the bridge would fall to it's timely demise. With all these forces equal, we achieve equilibrium in the gusset. Now, let's move onto the next gusset, the bottom center gusset.
The next gusset I will be explaining.
Like the previous gusset, I will give you a force diagram to help you visualize it.
OK! Let me start to explain the forces here now. The Fa is the applied force, and in this instance it is the bucket we applied to the bridge. The force of this object will be equal to the tension force of the strips above it. The bridge eventually broke because the force of the bucket was too big for the tension force to handle. Also note the tension forces that are horizontal. These forces must also be equal and with all of these forces equal, the gusset is at equilibrium.
Now I know what you're thinking. There is still one last gusset to go over. I have already explained all the forces on this bridge with diagrams, so there is no need for one here. To get a picture of it, go and look at the picture two pictures above. Basically, this has 3 forces, the tension force from the strip below and the compression forces from each of the tubes. These forces once again balance out to create equilibrium within the gusset.
Summary and Finale
Well, there you have it! In this entry, we covered exactly why this bridge was able to hold so much and what "magical forces" we causing it to stay in place. Once again, I would like to thank everyone for taking the time to read my partner and I's blog. You stay classy science and blog lovers!
