December 2017 Issue, Volume 85, No. 12American Journal of Physics, December 2017, Volume 85 Number 12

 

How tall can gelatin towers be? An introduction to elasticity and buckling

The stability of elastic towers is studied through simple hands-on experiments. Using gelatin-based stackable bricks, one can investigate the maximum height a simple structure can reach before collapsing. We show through experiments and by using the classical linear elastic theory that the main limitation to the height of such towers is the buckling of the elastic structures under their own weight. Moreover, the design and architecture of the towers can be optimized to greatly improve their resistance to self-buckling. To this aim, the maximum height of hollow and tapered towers is investigated. The experimental and theoretical developments presented in this paper can help students grasp the fundamental concepts in elasticity and mechanical stability.

 

Editorial

AJP Reviewers by Richard H. Price. DOI: 10.1119/1.5009924

Awards

2017 AAPT Award Citations at the Summer Meeting, Cincinnati, Ohio by Janelle M. Bailey. DOI: 10.1119/1.5012738

Papers

Computerized tomography platform using beta rays by Owen Paetkau, Zachary Parsons, and Mark Paetkau. DOI: 10.1119/1.5008267

The electromagnetic analogy of a ball on a rotating conical turntable by Keith Zengel. DOI: 10.1119/1.5002686

How tall can gelatin towers be? An introduction to elasticity and buckling by Nicolas Taberlet, Jérémy Ferrand, Élise Camus, Léa Lachaud, and Nicolas Plihon. DOI: 10.1119/1.5009667

Tau Zero: In the cockpit of a Bussard ramjet by Heinz Blatter, and Thomas Greber. DOI: 10.1119/1.5009919

Newton's theory of the atmospheric refraction of light by Michael Nauenberg. DOI: 10.1119/1.5009672

Alternative thermodynamic cycle for the Stirling machine by Alejandro Romanelli. DOI: 10.1119/1.5007063

Scattering from a quantum anapole at low energies by Kyle M. Whitcomb, and David C. Latimer. DOI: 10.1119/1.5003377

PHYSICS EDUCATION RESEARCH

Student understanding of first order RC filters by Pieter Coppens, Johan Van den Bossche, and Mieke De Cock. DOI: 10.1119/1.5003805

Apparatus and Demonstration Notes

The desktop muon detector: A simple, physics-motivated machine-and electronics-shop project for university students by S. N. Axani, J. M. Conrad, and C. Kirby. DOI: 10.1119/1.5003806

Back Of The Envelope

Welcome to the Back of the Envelope by Sanjoy Mahajan. DOI: 10.1119/1.5009646

BOOK REVIEWS

The Invention of Science: A New History of the Scientific Revolution by Danielson Dennis. DOI: 10.1119/1.5002680

BOOKS RECEIVED

American Journal of Physics 85, 963 (2017); DOI: 10.1119/1.5009445

 

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