Problem solving in statics and dynamics: A proposal for a structured approach

It has been the authors' experience that, even with the most careful presentation, students perceive the solutions to problems in statics, and especially dynamics, to be a "hodgepodge" of techniques and tricks. This is also born out by feedback the author's have received from colleagues and from the approximately 50 expert reviewers of the statics and dynamics books that the authors are currently writing. Interestingly, this state of affairs has changed little in the more than 40 years since the publication of the first editions of Meriam 1952, Shames in 1959, and Beer and Johnston in 1962 changed the way engineering mechanics was taught. In this paper, we present a formal procedure that we are using in the statics and dynamics texts we are writing. The procedure we are using is not new in that it derives from the approach used in more advanced mechanics courses in which the equations needed to solve problems derive from three areas or places: 1. balance laws (e.g., momentum,* angular momentum, energy, etc.); 2. constitutive equations (e.g., friction laws, drag laws, etc.); and 3. kinematics or constraints. On the other hand, it is new in the sense that we are applying it in freshman and sophomore-level mechanics courses. We will close with several examples from statics and dynamics for which we use our approach.