Stick With It! Helping Students Understand Free-Body Diagrams – A Magnet Activity as a Tool for Understanding

Abstract

For many students, introductory physics is an enormous hurdle to cross in their educational careers. Studies show that many students struggle with basic vector concepts and hold misconceptions of fundamental principles like Newton’s laws, ideas essential to the understanding of higher-order physics concepts and for achieving success in engineering and the other sciences. As it currently stands, common introductory textbooks provide insufficient guidance for students to learn the nuances of creating free-body diagrams. Such textbooks merely give a trivial example of a single object in equilibrium with only two forces on it when introducing the topic, and when giving more difficult examples, especially for multi-object systems, they fail to provide sufficient guidance on specific steps to create the free-body diagrams for each part of the system. Perhaps an even greater failing of these textbooks is the complete lack of emphasis on vector magnitudes, which can lead to unrealistic free-body diagrams that are unhelpful and can even be detrimental to student understanding. When drawn properly, free-body diagrams can be used as a quick reality check at the end of a problem.