title: Notation of physical equations no longer a problem.
abstract: Physical quantities and equations are used to define the laws of natural and engineering sciences. Clarity has been brought in equal measure into the the theory of physical quantities and the SI-system of units due to the basic work of Wallot and that of national and international institutions. For practical use in this paper, the most important rules and definitions for the formulation of physical equations are treated in an elementary form and the ease of their use is demonstrated in the following examples: speed of a car, capacitance of a plate capacitor, thermal emission of the cathode of an x-ray tube, oxygen uptake in cardiology, mole concentration and mass concentration of a substance in a solution. In addition, some important quantities and units of cardiology were summarized in a table.
mesh_terms: D002309:Cardiology / Q000379:methods*; D004738:Engineering; D006321:Heart / Q000502:physiology*; D006801:Humans; D008433:Mathematics; D010101:Oxygen Consumption; D055585:Physical Phenomena; D010825:Physics