Catapult Launch Makes an Impact

As the culmination of their unit on energy, students were tasked with designing and building catapults or trebuchets that could successfully launch paint-dipped cotton balls. 

Students spent two weeks working in teams to design and build their contraptions. Drew Craig, middle school science department coordinator, explained that “They worked within clear constraints related to size, safety and materials, while still having flexibility to experiment, test and iterate on their designs.” 

Ada Garberina and her partner used rubber bands, popsicle sticks and, she said, “a lot of hot glue” to build their launcher. 

Craig explained that, as with any science experiment, trial and error were essential components. “Students faced challenges selecting and testing effective materials, finding the correct tension using rubber bands, and understanding how geometry impacted the stability and effectiveness of their frames. They addressed these roadblocks through trial and error, testing prototypes, revising designs, and collaborating with classmates to troubleshoot and improve performance.

The experiment stood out to Gaberina, who said she had “never really worked on a project like that before. We got to immerse ourselves in it and figure it out.” 

On Launch Day in mid-December, students carefully set up their catapults on Evans Family Field near the IEC, placed cotton balls dipped in washable paint in the catapult bucket, and readied for blast off to test both distance and accuracy. 

Students flung the cotton balls onto the ground to measure distance; when measuring accuracy, one student on each team was tasked with holding a canvas several feet in front of each catapult, attempting to have the cotton ball connect with the canvas. 

“One or two people got hit with paintballs,” Garberina said. “Not me, thankfully!” 

The day was a highlight for Craig, who enjoyed “watching students test their catapults and celebrate their efforts, especially as they launched paint-covered cotton ball projectiles and embraced the fun (and mess) of hands-on science. I hope students walked away with a deeper understanding of how scientific concepts apply to real-world problems, as well as increased confidence in problem-solving, perseverance and learning through iteration.” 

Indeed, though the paint splatters have washed away, the lessons in kinetic and potential energy, energy transfer, and forces made a lasting mark. 

Garberina reflected, “It’s one thing to visualize how it’s supposed to work with accuracy, with precision. But then seeing it actually play out with the experiment we created was something else.”