Work of breathing When there is increased gas flow resistance, the optimal respiratory rate decreases. This work (generally during the inhalation phase) is stored as potential energy which is recovered during exhalation. A pressure difference is required to overcome the frictional resistance to gas flow due to viscosity, and to provide non-elastic components of movement of the airway tissues to accommodate pulmonary volume change. Total work done against non elastic forces is 35% of total. Work is defined as a force applied over a distance. The SI unit of work is the Joule, equivalent to a force of 1 Newton exerted along a
Scientific law water); although in many systems (notably biomacromolecules and minerals) the ratios tend to require large numbers, and are frequently represented as a fraction. More modern laws of chemistry define the relationship between energy and its transformations. Scientific law The laws of science, also called scientific laws or scientific principles, are statements that describe or predict a range of natural phenomena. Each scientific law is a statement based on repeated experimental observations that describes some aspect of the Universe. The term "law" has diverse usage in many cases (approximate, accurate, broad, or narrow theories) across all fields of natural science (physics,