Helping Students Draw Correct Free-Body Diagrams

Abstract

As physics instructors, we try to help our students learn physics. But most of us begin to realize that our students are not learning as much as we hope they would. As we listen to our students, we begin to see some of their difficulties. Some of their difficulties are expected, but some are unexpected. One such difficulty is drawing the force diagram, or free-body diagram (FBD). Knowing the importance of being able to draw correct FBDs, we try to help our students by presenting the necessary steps clearly. Unfortunately, many times, what seemed clear to us isn’t as clear to our students. So, how can we help our students draw correct FBDs? In this paper, we present an approach we used in lectures to help our students draw FBDs correctly. We also present some encouraging preliminary results from a comparison study of two introductory physics classes. As you will see in the discussion of our approach, we will be highlighting a few things, so in this paper we will refer to our approach as “the highlight approach.”