Resumen de Free-Body Diagrams and Bogus Work
There are currently two quite different approaches to the introductory, calculus-based course for engineering students. The traditional course is strictly mechanics, while the newer, energy-first course, is based on thermodynamics. Part of the early impetus for this change was the perceived student confusion arising from the use of a quantity called pseudowork. This quantity uses the external force acting on an object and, as such, is intimately connected to the free-body diagram (FBD). In the energy approach, a force may act on a body but does no work, in the thermodynamic sense, depending on the displacement of the point of contact. That force would then not appear explicitly in the solution. There is a resulting significant difference in the importance of the FBD in the two approaches. A correct FBD can guide the student in determining which fundamental law should be used to solve a problem.
