Smashing Pumpkins

Abstract

Exploding pumpkins with rubber bands remains a popular demonstration of the conversion of spring potential energy into kinetic energy. Videos of laughing and squealing children and adults being pelted with pumpkin fragments have millions of hits on YouTube, and the activity has even been featured on talk shows like “The Tonight Show Starring Jimmy Fallon.” This light-hearted activity is an excellent demonstration of multiple concepts in physics and engineering. In this paper, we examine and analyze a large data set collected by Jon Orr, a Canadian high school math teacher who authored a Desmos activity on learning scatter plots using this fun demo. In this paper, we expand upon Orr’s original work and explain the physics behind this activity. We analyze Orr’s data and use this analysis to explain how the number of rubber bands required to rupture a pumpkin depends primarily on the effective spring constant of the rubber band and the thickness of the pumpkin wall. We hope to provide inspiration for teachers using this demo to teach STEM concepts in the classroom.