pendulum waves

snacks that swing

The seven snack packages follow a mysterious choreography as they swing on strings affixed to a ruler about two feet in the air.

With a little push, they swing forward as one, then a wave ripples across the line. Next, the Cheezits and Goldfish swing in one direction while the fig and granola bars move in the other. After a freeform portion, the dancers slowly return to their original line before stopping. 

What causes the snacks' pendulum wave? This is the challenge students grappled with in College Preparatory Physics, taught by Frank Noschese and Dan Longhurst.

american foods

hands-on physics

John Jay's physics classes are known for hands-on experiments. Students experience friction by having a tug-of-war in the hallway—one team in socks, the other in shoes, and jump on scales to see the relationship between velocity and weight. 

"Creating pendulum waves allowed students to apply their physics knowledge about how a single pendulum behaves to design something more exciting and creative.” said Noschese.

Julia, Olivia and Hope, the creators of the pendulum wave featuring snacks, mention the hands-on aspect of the class as a highlight. They had fun with their project, setting a video of their wave to Miley Cyrus’s “Party in the U.S.A.” They also nailed their calculations, determining the length of their longest pendulum which informed the length of the others.


reaching a conclusion about gravity

This year's pendulum wave materials included squishy toys, Legos and school supplies.

Declan, Will and Chris​ chose to create theirs with fifty-cent coins. Because all of their pendula  weighed the same amount, it became quickly apparent that the only factor determining the different paces was the length of the strings.

"Pendulums swing because of gravity," the students discovered. "Weight doesn't matter. It's only the length that makes one swing faster or slower than another."