About The Unit, Structures…

What did I learn during this unit…

When we introduced to the unit, my first thought was that structures weren’t related to science, but as we went on in this unit I started seeing how it connects to science. We looked at different types of structures and wrote down questions about it, about the shape, what is unique about it, how they built it,…

My Experiment…

My scientific research question is: ‘ Which cardboard bridge ( truss, arch, and beam bridge ) would be able to hold the most weights of 100, measured in grams? ‘


Independent variable: The bridges will be made out of cardboard, they will all be the same height and length.

Dependent variable: Which bridge is the strongest by putting weights in the center of the bridge, it will be measured in grams.

Controlled variables: They will all be the same height and length (I won’t estimate the length or height, I will make them 20 by 10), after 10 seconds if it didn’t fall over (I will have a timer, to make sure it is exactly 10 seconds), I add another weight to my bridge, the same type of cardboard will be used for every bridge

Here is a little explanation about how I am going to do my experiment

I made three types of bridges, truss, arch, and beam bridge. I choose this type of bridges because they are the most common bridges. They will have the same height and length (10 by 20), so it is fair. I am interested in which of these three structures is the strongest by putting weight on the bridge. I will focus on one bridge at the time, first the truss, then the arch and finally the beam bridge. I will have a timer to see how long it stands up and to make sure after every 10 seconds I add a weight of 100g in the center of my bridge. Eventually, the bridges will start to bend or even fall over because there will be to much weight… How will I know which bridge is the strongest? In the end, I will count how many weights they could hold, the bridge that could hold the most amount of weight wins. What do I do if there is a tie? I will look at the timer that tells me how long they have been standing. The one that had been standing the longest is the winner.


There was also a beam bridge, but I forgot to take a picture of it…

This was the prediction of my experiment: “I think the truss or the beam bridge will stand the longest, I am not sure which one will start to bend first because they are both strong and stable. The arch will definitely bend at first because arches are not very strong and there is nothing that keeps the middle of the arch up.” 

Here is what I wrote for the conclusion using my data: ” My research question is, which bridge is the strongest. In the graph, you can really see that there is a big difference between the bridge that can hold the most and the least amount of weights. As I already said in the ‘Data Analysis’ the truss could carry the most weight, that means the truss is the strongest bridge between beam and arch bridge in cardboard.”

Here is my raw data about my experiment

Data Analysis of My Graph

The blue stripe line doesn’t mean anything, it is just to show how far apart the results are from each other. The dots show how much weights of 100g the bridge can hold, the blue dot is above the type of bridge that has been used.  The arch can hold around 500g, the beam can hold around 700g and the truss can hold around 1800g which is also 1kg and 800g. As you can see the truss can hold the most amount of weight and the arch the least.




If you want to know more about my experiment here is a link to it https://docs.google.com/document/d/1rz2pGVq0o-vMG8dTuL1pHWiFPBWUkbA2VbbfHAasYuk/edit