The understanding of the physical properties of fluids enabled several technological advances. For instance, it is worth mentioning the production of aircrafts, ships and cars with optimized design, which reduce the co-called drag force dramatically. Here we discuss fundamental concepts of fluid mechanics, as the drag force acting on a particle moving in a viscous fluid as proposed by Stokes in 1851, terminal velocity, Reynolds number and their connection with the kinetic theory of gases. Counter-intuitive phenomena, as the insensitivity of the terminal velocity of a particle moving under the action of gravity in a medium with distinct densities for low Reynolds number, will be discussed in detail.
Keywords:
laminar flow; terminal velocity; Stokes' Law; Reynolds number; kinetic theory
