Topics
Free-body diagrams, Fundamental interactions, Learning and learning models, Educational aids, Educational assessment, Science education, Knowledge, Statistical analysis

Introductory physics classes typically teach free-body diagrams, in which a number of force arrows stem from the center of mass of an object, as the primary problem-solving model for working with forces.1,2 These diagrams enable the calculation of the total force in each coordinate direction, using the angle and magnitude of the individual forces applied. While free-body diagrams are commonly used, research has shown that learners (K–16) and teachers do not have a firm grasp of what forces are3–5 and often struggle with foundational physics concepts such as the idea of forces as interactions.4 To represent seemingly abstract force scenarios, force and motion practice problems are often accompanied by a picture or online simulation. In these models, the forces are represented differently than in the free-body diagrams, causing a disconnect between the original depiction of the scenario and the mathematical problem-solving approach (Fig. 1). This disconnect...

AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.