It has become increasingly apparent in our combined years of teaching engineering subjects that there is a discontinuity between how related subjects are taught. By that, we mean that fundamental principles of mass, energy and momentum are indifferent to the application, yet they are introduced and utilized very differently in various engineering courses, specifically those in the general area of solid mechanics versus those in the fluid and thermal sciences. One example of this disparity is the conservation of energy principle, one of the two most fundamental of principles for which all things appear subject to without limitation. Also known as the 1st Law of Thermodynamics, the statement simply says “energy cannot be created nor destroyed.” This implies that, within these broad but absolute limits, energy can be converted from one form to another or transported from one place to another, or both, but that the total energy remains a constant.
This 1st Law of Thermodynamics is taught earlier in the curriculum from its namesake, thermodynamics. In fact, most introductory statics and dynamics courses do teach some form of the conservation of energy, but usually call it “energy methods.” The plural form “energy methods” indicates that there is more than one, which can be readily observed in most statics and dynamics textbooks. Unfortunately, these methods are only special-cases of the conservation of energy principle. At no time, however, in any statics and dynamics textbook that we have seen, is the full conservation of energy principle utilized, which is unfortunate for reasons of consistency and continuity in the curriculum.
It is the intent of this paper to show, through an example, that the same basic form of the conservation of energy can and should be utilized throughout the curriculum, starting with basic statics and dynamics and progressing into thermodynamics and the rest of the curriculum. This would indeed help student comprehension and retention of this very important principle in implication and application.
The motional effects of the maxwell æther-stress