Conference Proceeding

Guided Discovery Modules for Statics

Tarawneh, Constantine, Vasquez, Horacio, Wrinkle, Robert D, Kypuros, Javier Angel, Knecht, Martin William

2012

Overview

A Guided Discovery Module for Free Body DiagramsStudents notoriously struggle to master the concept of free body diagrams. In Statics, forexample, they often fail to identify reaction forces, include nonexistent forces, and sketchdiagrams that are not in static equilibrium. Confusion arises in distinguishing internalfrom external loads and their impact on free body diagrams. This paper presents aGuided Discovery module designed to reinforce proper conception of free body diagramsby physically illustrating the consequences of not accounting for all the correct loads.Guided Discovery is a novel methodology that borrows aspects of challenge-basedinstruction and discovery learning. The method is designed to facilitate students’ paths todiscovery of key concepts that are often misinterpreted or not readily mastered. Themethod is optimized for short, in-class activities. It is a low-cost, active-learning methodintended to bring laboratory-like experiences into the classroom to improve conceptmastery and elucidate common misconceptions. The intent is to target concepts thatstudents commonly fail to master and that negatively impact learning outcomes in latercourses. The authors provide a brief overview of the methodology with illustrativeexamples and a summary of assessment results of former modules.The focus of this paper, however, is a new module that has been recently piloted inStatics courses. The module uses a variety of spheres (e.g. Ping-Pong balls, racket balls,baseballs, etc.) stacked in various orientations within cylinders (e.g. coffee cans,tennis/racket ball containers, etc.) of varying radius with and without a base (i.e. the baseis removed from some cylinders). The spheres are stacked in the cylinders to illustratestatically stable and unstable systems. Students are challenged to devise a staticallystable (unstable) system and prove its stability (instability) through proper use of freebody diagrams; they work in small teams to resolve the challenge. They must validatetheir analysis through experimentation and justify their conclusions to their peers. Theywork through several different scenarios where the cylinder diameter, sphere radius,cylinder mass, and sphere mass are varied. Using the cylinders and spheres, they canimmediately test their conclusions and determine if they made a mistake or used aninappropriate assumption. The module is designed to show how the lack of accountingfor a reaction force can readily render a false positive – a system that is seemingly stablebut in actuality is not. This paper details the design and implementation of this moduleand provides preliminary results that assess the efficacy and impact on concept mastery.

• Publisher: American Society for Engineering Education-ASEE
• Subject: Balls / Classrooms / Coffee / Confusion / Containers / Cylinders / Diagrams / Diameters / Discovery / Educational activities / Efficacy / Experimentation / Experiments / False positive results / Human body / Learning / Learning outcomes / Misconceptions / Modules / Spheres / Static equilibrium / Students / Teamwork / Tennis