Resumen de Adding Value to Force Diagrams: Representing Relative Force Magnitudes
Nearly all physics instructors recognize the instructional value of force diagrams, and this journal has published several collections of exercises to improve student skill in this area.1�4Yet some instructors worry that too few students perceive the conceptual and problem-solving utility of force diagrams,4�6and over recent years a rich variety of approaches has been proposed to add value to force diagrams. Suggestions include strategies for identifying candidate forces,6,7emphasizing the distinction between �contact� and �noncontact� forces,5,8and the use of computer-based tutorials.9,10Instructors have suggested a variety of conventions for constructing force diagrams, including approaches to arrow placement and orientation2,11�13and proposed notations for locating forces or marking action-reaction force pairs.8,11,14,15
