Blast from the past: Catapulted water balloons injured teachers, leading to rule changes

May 9, 2018 — by Kaylene Morrison and Sandhya Sundaram

After catapulted water balloons injured teachers in 2011, new regulations were put in place.

Later this month, on a date that science teachers still hadn’t determined at the time The Falcon went to press, physics students will come together in the quad to propel water balloons with handmade catapults using physics principles. This activity has been going on for years, but no year was more memorable or significant than 2011.

During lunch on a sunny day in May, physics students lined up their handmade catapults in the quad as they gleefully prepared to launch water balloons at defenseless teachers. Expecting harmless entertainment, the students were surprised when several teachers, including AP Chemistry teacher Kathy Nakamatsu and English teacher Ken Nguyen, appeared to be uncomfortable after several rounds of launching.   

After getting an X-ray for her injury in 2011, Nakamatsu found that the balloon’s impact had fractured her right thumb in multiple places.

I was in shock first. I didn't realize that my thumb was broken,” Nakamatsu said. “I remember thinking I would be able to teach after lunch, but as my thumb started swelling and throbbing, I realized [teaching] wasn't going to happen.”

Since this incident, Nakamatsu has avoided participating in this annual tradition, fearful of what may happen.

Nguyen was injured much less seriously; a balloon bent his finger backwards, ricocheted off and hit his eye, causing a contact lense to pop out. The experience didn’t faze him, however. He has participated every year since then and plans to participate this year as well.   

The lenient regulations on the structure of the catapults were partially at fault for these injuries. That year, a group had reinforced their project with surgical tubing, which allowed the arm to move at a greater velocity, and they had also launched larger balloons. This, along with a limited space for the teachers to stand and the large number of catapults that were constructed that year, led to the injuries.

To prevent further injuries from occurring, the physics teachers have created certain limits on how powerful the catapults can be, as well as the size of the balloons. Additionally, the teachers now have unlimited space to move around.

AP physics teacher Kirk Davis said that the goal of the assignment is for the students to gain an understanding of the physics of catapults while also being able to have the satisfaction of designing and building something.

Senior Vivian Luo participated in the water balloon project last year in her physics class for the chance to earn extra credit.

Her group built their catapult with wood and other materials from Home Depot. The opportunity to build the catapults reinforced knowledge learned in the course.

We could use calculations that we’ve learned about launching and speed to determine where it will go and where we should position it,” Luo said.

Participating students got a testing day to practice shooting at a target, and shooting at the teachers awarded her points in addition to the credit she got for building the contraption.

“Everything was extra credit, so even if it didn’t work, it didn’t hurt us it was just time consuming,” Luo said.

With the new regulations having been in place for several years, people haven’t been as worried about getting injured. Several teachers, including science teacher Kristofer Orre, English teacher Erick Rector, principal Paul Robinson and Nguyen now try to catch the balloons and throw them back at the students.

“Usually, it's on a nice day so even if you don’t catch it, the water balloon gives you a nice, cool shower,” Nguyen said.