Goal: Our goal during the Fire Away! project was to create a trebuchet or catapult that would fire a clay projectile. Our only restriction was that the trebuchet couldn’t be larger than one meter in any direction.
Design: We made some modifications to our design. We changed the length of the trebuchet arm, because it would allow our projectile to travel farther. We added more rubber bands for more spring potential energy. More potential energy means more distance. During our experiment we found that a 1:2 load to effort to load ratio for a trebuchet arm launched the projectile the farthest. Our experiment included multiple trials in which we changed the effort to load ratio. We then measured the distance the projectile traveled. We found that when we had a ratio of 1:1 it went an average of six meters. This distance was longer than the rest of the ratios that we tested so far. We then found that the average distance for the 1:2 ratio was seven meters and one third. This was the longest distance that any of our projectiles had traveled.
Calculations: Distance horizontal: 22m Time in air: 3.2s Velocity horizontal: 6.875m/s 35mph Velocity vertical: 15.68m/s Velocity total: 17.1m/s Release angle of projectile: 66° Spring constant: 40N Spring Potential Energy: 43.12J Kinetic Energy of the projectile: 1.5J Percent of energy converted: 17% Distance vertical: 25m 82ft
Selling Points: The trebuchet can launch a 10 gram projectile 25 meters vertically and 22 meters horizontally!!! It is also very consistent.
Reflection: This time around my team worked well together. One peak was that we got our trebuchet to work consistently. One valley was that one group member didn't do his share of the work. I felt that I pulled my weight during this project and helped out a lot.