Cantilevers are all around us. They are very simple, but so useful. They help hold things up in the air and are used in lots of construction projects. Have you ever used a lever like a seesaw or scissors? Well, a cantilever is like a lever. But the fulcrum or point where its supported is at the end of the lever instead of the middle. The cantilever is used to support heavy things, rather than lift or move them. Look around you. How many cantilevers can you spot? Sofia Puerto, a civil engineer, can tell us all about them. Cantilevers are a type of structure only attached to one end. You could actually make your arm work as a cantilever. If you extend your arm forward or sideways, it is still attached to your body, but the other end, where your hand is at, its ready to hold things. Try it yourself. What kind of things can you hold? What is the heaviest thing you can hold without bending your elbow? So, what are cantilevers actually used for? So in buildings, for example, cantilevers are used in balconies. But in roadway projects, cantilevers can be used in light posts, for example. So, basically, cantilevers can be used in any type of project. How do you make sure the cantilevers are doing their job? Well, we know that a cantilever is working when it is holding things up. When it is not working, the cantilever starts to bend or deflect. The weight or load of what the cantilever is holding can’t be supported by the cantilever. Sofia can show us how this works. I’m going to demonstrate what bending is with a card and two paperclips I found around the office. First, I’m going to hold my card as a cantilever, by grabbing it at one end and leaving the other end free. If I grab my small paperclip and attached it to the end, my cantilever actually works pretty well. It’s not bending. Now, if I attach, to the end, a bigger paperclip, it actually bends a lot. So my cantilever stopped working right. But how do we fix this problem if the cantilever stops working? Let’s check back with Sofia. Now, what would happen if I rotate my card 90 degrees and grabbed it from the other end? If I attached a bigger paperclip that previously was causing so much bending to the free end of this new cantilever, my cantilever actually works pretty well! So, how well a cantilever works also depends on how long it is. Therefore, the engineer has to find a perfect equilibrium between the geometry of the cantilever and how much weight it is holding, to not have any bending. Start building your own cantilever on Curiosity Machine! How much weight will you be able to hold?