Students participate in lab to predict the movement of spheres in motion. Students participate in lab to predict the movement of spheres in motion. Students participate in lab to predict the movement of spheres in motion.
Professor Troesch wasn’t certain whether his students sleep deprived and eager for Spring Break, would give his new Rolling Ball Competition the attention he hoped, but with pride on the line, he needn’t have worried.
In teams of three, they were set with the task of displacing a ball on an air track to a predetermined starting position. The winning team would be the one that calculated the largest deflection of the cart such that the rolling ball stayed on the channel through more than 2.0 oscillations. Basically, who could move the track the furthest from rest while keeping the ball from falling for the most oscillations?
First, they’d need to choose from an array of spheres; each of different weight, material, and diameter.
From there, it was time for some calculations. They’d need to take into account the weight and the natural period of the cart and channel, where to place the ball, the physical properties of their chosen ball, and more. Then, it was time to turn theory into practice.
It turns out that predicting the motion of free bodies from rest isn’t a simple task and some teams were able to do so more adeptly than others. But with ten minutes to make adjustments to their original hypotheses, all the teams were able to successfully keep the ball on the air track for the required 2.0 oscillations.
“The enthusiasm and collaboration are what I like to see,” says Professor Troesch. “At the end of the day, they’ve gained some practical experience and improved their logic skills as well. Besides, it’s nice to let them get their hands on something real. The value of practical experience is invaluable to our students. I want them to have the opportunity improve their observational skills by encountering complex dynamical systems first-hand.”
So, who won? As with most scientific experiments, it’s unclear. Certain teams displaced the track further than others but managed fewer oscillations. And later teams had the benefit of the accumulated experience of the others.
According to Professor Troesch, the value was always in the journey or put more succinctly, “They all won.”
So what’s next for Professor Troesch’s class?
“I have this idea about balloons in the downstairs hallway,” he says with a wry grin. We’ll keep you posted.
Equipment was bought and provided by the ABS Professorship funds.