Find the time for two neighbouring molecules to slide past each other. Note that this is independent of the atom spacing. Terminal Velocity An object moving through a viscous fluid has a resistive drag force exerted on it by the fluid. It means there is a terminal speed which is the maximum speed for the given conditions. The drag force is affected by both shape and speed of the object, through the drag coefficient, b and the speed, v .
C D is the drag coefficient produced by the shape of the car.
For most cars C D lies between 0.2 and 0.5. Stokes' Law and Terminal Speeds Stokes calculated the drag force on a sphere at low speeds as , where h is the viscosity, r is the radius, and v , is the speed. Terminal speed for a sphere falling under gravity. Find the radius of the droplet. Consider a solid cylinder of fluid, of radius r inside a hollow cylindrical pipe of radius R .