Evidence of Work

The Task :

For this project, we had to build a catapult, trebuchet, or any launching device to send a projectile has far as possible. This device had to be portable, reusable, and had to have a stable base. Also, none of the dimensions could surpass 1 meter and it had to have an effort and a load. Once we had our first prototype, we had to make 5 modifications to make it better. I worked on this with Analiese Engler, Sola Takeda, and Aidan Baggs. We helped each other distantly by letting each other know what worked well for us and what didn't. We also helped each other with our designs.

5 Modifications :

1. Lighter Projectile - In the original trebuchet, I was using a large eraser for my projectile. This wasn’t working too well because the weight of the eraser brought it down pretty quick. In the new trebuchet, I use a key for my projectile. This works a lot better because it is light enough to stay in the air for longer, yet heavy enough to fly a good distance.

2. Put the Projectile on A String - As I said before, I was using a heavy eraser for my projectile. The eraser was sitting in the spoon. Now, the key is tied to a string which is hanging off the end of the spoon. With this new addition, the projectile gets more of an arch when it is released. The eraser flew more vertical and less horizontal.

3. More Weight on Arm - In the original trebuchet, it was only rubber bands creating the force to launch the projectile. Since then, I tied on a water bottle with some water in it for extra weight. The added weight creates more potential energy, so when the trebuchet is released, it converts to kinetic energy which means that the trebuchet will launch the projectile much faster, resulting in a farther distance.

4. Load to Effort Ratio - In the original design, the axle was basically on top of the rubber bands. With my current design, they are much farther apart, resulting in the rubber bands stretching more. This means that there is a greater tension between the broom and the base, which makes the trebuchet launch faster. This will make the projectile fly farther.

5. Higher Legs/Base - In the new design, the contraption sits on a table and can be moved to higher or lower places. In the original design, it sat on the ground. When the base sat on the floor, the broom would hit the ground when it was released, so the projectile didn’t get as good as an angle. A higher base is helpful because it lets the arm fully rotate and release the projectile at a better angle.