1 AFib reduces the ability of the atria to pump blood into the ventricles, and usually causes the heart to beat too rapidly. 2  One-half million new cases of atrial fibrillation are diagnosed every year in the U.S., and billions of dollars are spent annually on its diagnosis and treatment.
noun, (used with a singular verb) 1. the branch of mechanics that deals with the motion of air and other gases and with the effects of such motion on bodies in the medium. Compare aerostatics (def 1). Origin of aerodynamics.
In aerodynamics, drag refers to forces that oppose the relative motion of an object through the air. Drag always opposes the motion of the object and, in an aircraft, is overcome by thrust. Types of Drag. There are many different types of drag. The most commonly encountered are: Parasitic Drag, composed of Form Drag, which is the result of the aerodynamic resistance to motion due to the shape of the aircraft, Skin Friction Drag, which is due to the smoothness or roughness of the surfaces of the aircraft, and.