Radii

[[File:Circle-withsegments.svg|thumb|right|Circle with:

unit of measurement

distance from a massive body where the escape velocity equals the speed of light

mean distance from the Earth's center to its surface

measure of a channel flow efficiency

radius of a circle which best approximates a curve in a given point

physical constant providing length scale to interatomic interactions

distance from center of mass to axis of rotation

mathematical concept

unit of radius equal to the total radius of the planet Jupiter

radius of the circular movement of an electrically charged particle in a magnetic field

of a galaxy

measurement of light ray bending from a gravitational lens

concept in optical lens design

maximum range to which a vehicle can travel, complete its operational activity, and return to its origin without refueling

measure of the size of atomic nuclei

diameter of smallest circle a particular automobile or similar vehicle can turn along

diameter of a sphere of the same volume as an irregularly-shaped subject

length scale at which rotational effects become as important as buoyancy or gravity wave effects in the evolution of the flow about some disturbance

property of colloids and macromolecukes

minimum particle size from which an aggregate is thermodynamically stable

shortest allowable design radius for the centerline of railway tracks

parameter of solute diffusion