Gwyneth K. Shaw Photo
Jean Zheng pulled on the wood, fighting the heavy-duty tension springs to bring a homemade catapult back far enough to load it.
Struggling — and giggling — she finally had to ask for help. Apparently, the fourth-year Ph.D. student in mechanical engineering has brains, but not much brawn.
With assistance from Kayla Matheus, Zheng (pictured) wrestled the apparatus down, inserting a “key” that held back the catapult. She put a squishy, Nerf-like ball into the black plastic rectangular container that served as the cup.
“Clear!” she yelled, warning anyone standing nearby in Yale’s Davies Auditorium to take cover.
Then she tugged on the blue nylon rope attached to the key, dislodging it and releasing the arm. With a rush of movement and a soft “ping” from the springs, the ball flew into the air, arcing down into the auditorium’s seats. Zheng just missed one of the red bins — with points assigned to each — scattered about the rows.
Red bins marked the distances in the auditorium.
Friday’s lunchtime festival of flinging wasn’t a typical day for Zheng or the other students and alumni who gathered in Davies to test the laws of physics. The catapult event — the spring-loaded apparatus was one of two contraptions — was part of Engineers Week, which was celebrated on college campuses across the country.
Zheng was a co-organizer of the events at Yale’s School of Engineering and Applied Science, aimed at convincing undergraduates to take up a hard science major. Other activities included lunches with faculty members, an ice cream social, and a trivia night featuring professors.
Stuffed mini versions of R2-D2, Yoda and Chewbacca await their flights.
But the catapulting frenzy was mostly about fun: Nerds launching Nerfs, not to mention some furry “Star Wars” characters (pictured).
Zheng’s co-conspirator, Enping Hong, said the gatherings gave students a chance to mingle. Since the engineering school is divided into four departments — Hong is a biomedical engineering grad student — it’s rare for everyone to get together.
Hong (pictured) spent a lot of setup time tinkering with the slingshot-like catapult that was clamped to a long desk alongside the spring-loaded machine. The slingshot, made of rubber tubing, was less successful than its springy competition; balls occasionally went backward or up instead of being launched into the auditorium.
Kayla Matheus and Max Sutter test out the slingshot model.
The balls behaved exactly as Hong expected, he said: The round ones flew much farther, while the football-shaped balls lost speed quickly.
“You need to be throwing it to have that shape work,” he said of the footballs.
Medical student Kofi-Buaku Atsina wrestles the spring-loaded catapult.
Yoda, R2-D2 and Chewbacca were more valuable as comic relief than as projectiles.
Zheng and Hon had originally envisioned the catapult stationed outside, until Friday’s weather drove the event indoors. But residence in the dark recesses of Davies had one major advantage: Because the auditorium seats are set on a downhill slope, the balls rolled right back once they hit the ground, another lesson amid a hands-on physics adventure.