Engineering Students Aim for Accuracy in Unique Final

For some, finals mean reports, tests and maybe a poster presentation or two.

But for the students in Rockhurst University’s engineering dynamics class, it also meant building, calibrating and testing a team-designed and built catapult as part of the first-ever engineering dynamics launch competition Monday, May 5.

Three teams from Rockhurst’s engineering dynamics course competed to see whose device could land a tennis ball closest to a target 82 feet away — a distance announced just before the competition started. A group from Rockhurst’s general physics course also participated in the launch. Mark Pecaut, Ph.D., the assistant professor of physics who organized the competition alongside Mike McCoy, P.E., M.Ed., professor and instructor/lab manager for the physics department, said that variable distance was what made for a challenging prospect for the students.

“It’s more than just building a machine that can launch a tennis ball as far as possible,” Pecaut said. “The students had to not only build, but they had to measure the machine's capabilities and they had to calibrate them. That’s crucial, because in real life, you calibrate things — you don’t just say, well, my calculations are correct.”

Josh Pudlowski, a sophomore civil engineering major, said it took his three-person team about four to five weeks to design, build, and test their machine. That included some time for trial and error, he said.

“At first in our minds we had a different design,” with springs instead of elastic bands, Pudlowski said. “But we realized it wouldn’t work, so we had to adjust.”

As part of the final, students wrote papers detailing their experiences, presenting not only the ideas behind their design, but also the calculations and data that went into fine-tuning their catapult.

“It really was a lot different than any other final I’ve had,” said Pete Peterson, a junior physics major. “It was a lot of fun.”

Pecaut said he hoped the students enjoyed the experience, but also received an immersive lesson in the sort of applied physics that is important to engineers.

“Building these things supports a lot of ideas that are presented in the class,” he said. “They have to think about how the energy is stored and converted and they have to think about it quantitatively.”