Trebuchet Essay

For my PJAS science experiment this year, I chose to test and experiment with the main physics behind a trebuchet, a medieval weapon. A trebuchet, in simple terms, is a mechanical device that that can throw a wide range of projectiles with very good accuracy. These projectile can range in weight from a tennis ball, like I am launching, to the heaviest object being a large stone. The trebuchet that I will be experimenting with was designed sometime in the twelfth century. This version of the trebuchet utilizes the force of gravity to pull a heavy counterweight to the ground. The ancestors of the modern trebuchet were first built in the sixth century. However, these devices were human powered; they did not use the concept of a counterweight being

The first trebuchets that were ever designed were probably built to break down castle walls or any type of barrier that stood in the way of the army. At the time, the trebuchet was preferred over the catapult was because of the extended range and its greater accuracy. The design was also extremely portable, since it could be built on wheels. During these early years of existence, the trebuchet was a very powerful weapon. Not many armies had one and it could launch a stone the farthest of any weapon of the time period. The common trebuchet, the same design as the one I am designing, is constructed with a base that has a revolving intersection at the top. Connected to this intersection are the trebuchet's key components. The longer arm that is connected to the sling, which is the component that holds the item that is going to be launched, and the shorter arm, the arm that is connected to the heavy counterweight. In a successful launch of a trebuchet, the counterweight is first released; it uses the force of gravity, as I mentioned before, to pull the counterweight to the ground. The chain reaction then pulls the sling forward and upward at high velocity. Finally, the projectile is then launched forward an extreme distance and with extreme

Tennis balls have an average mass of fifty-eight grams. I chose to launch a tennis ball because of its size, its easiness to spot, and its bright color. It also stands out, so in the case of a misfire, it is noticeable and would not go crashing into something or through a window and break something. Based on a simulator, I predict my trebuchet to launch the tennis ball over one-hundred meters. Even though a trebuchet is typically made of wood, I plan to make my replica out of PVC piping that can be purchased at the local hardware store. The scientific name of PVC piping is Polyvinyl Chloride. In North America and Europe, Polyvinyl Chloride is a thermoplastic vinyl made of 57% chlorine and 43% carbon. I chose to construct the trebuchet out of PVC piping because it is easy to cut, manage, and assemble with readily available joints. I predict that the hardest part of my design and constructing phase will be planning and buying the correct pieces to complete the design of the trebuchet in the first