A physics lesson with projectile pumpkins

Tuesday afternoon was a sight to behold at Landels Elementary, as one by one, students launched grapefruit-sized pumpkins across the campus field, hoping to hear a satisfying splat when they hit the ground.

While pumpkin destruction sounds like a fun way to blow off steam, the spectacular display hosted annually by the school has a purpose beyond seasonal produce smashing. The parent-led activity, now in its fourth year, gives young children a glimpse into the world of physics and ways to harness energy that can send fruit flying.

Landels parent Tushar Moorti began teaching the classes and wheeling out the medieval-looking trebuchet — about the size of a golf cart — to show students scientific concepts in action. Dubbed the “Punkin Chunkin” class, the afternoon activity mimics the annual World Championship Punkin Chunkin event in Delaware, where contestants use outrageously large devices, including pneumatic cannons, to launch full-sized pumpkins thousands of feet.

Moorti decided early on that having kids build their own trebuchets was going to be way too problematic, and opted for one large device that students can use to test what they just learned in the classroom. Attendance wasn’t great at first, he said, but after making some improvements to the rig so the pumpkins would fly farther and adding new concepts to the class, Punkin Chunkin became a hit at Landels.

Because students are as young as kindergarten and first grade, he said it’s important to stick to basic concepts like Hooke’s Law — a simple equation that calculates force — and avoid complex topics like ignition and combustibles as much as possible.

“We really try to minimize it to just understanding a simple concept,” he said.

Older students who take the first class, which focuses solely on leverage using trebuchets, can move on to the “Double Chunk” class that took place on Nov. 7, where students learn about springs and how slingshots can be used to launch pumpkins. There’s a little more math involved in the second class, Moorti said, and he hopes that the early exposure to the concept of force means it won’t feel too foreign when kids start to dig into advanced math and physics in middle and high school.

“Once they learn the language it becomes less daunting,” he said. “Hopefully the students will be able to learn more easily because they know in the backs of their minds, ‘Oh, I know how this works.'”

Punkin Chunkin is one of dozens of classes in Landels Enrichment Activities Program (LEAP), a circuit of of extracurricular activities hosted by parents and volunteers at the school. The topics range from arts and crafts to science and engineering, and about one-third of all students at the school participate in at least one of the classes, Moorti said.

Kids who join in on the pumpkin-launching activity are excited to see how far they can get their pumpkins to fly, he said, but the real treat is seeing the pumpkins shatter when they hit the ground.

“When it explodes, you can hear the cheers,” he said.