کروند ِ لورنتز karvand-e Lorentz
*Fr.: facteur de Lorentz*
In → *special relativity*, an important parameter which appears
in several equations, including → *time dilation*,
→ *length contraction*, and
→ *relativistic mass*. It is defined as
γ = 1 / [1 - *(v/c)*^{2}]^{1/2} = d*t*/dτ,
where *v* is the velocity as observed in the reference frame where time *t*
is measured, τ is the proper time, and *c* the
→ *velocity of light*. Same as *Lorentz γ factor*. → *Lorentz*; → *factor*. |

کروند ِ بازتاب karvand-e bâztâb
*Fr.: facteur de réflexion*
The ratio of total flux that is reflected from a surface to the incident
flux. Also called *reflectance*, *reflectivity*. → *reflection*; → *factor*. |

کروند ِ مرپل karvand-e marpel
*Fr.: facteur d'échelle*
*Math.*:
A number which scales, or multiplies, some quantity. In the equation
*y = Cx*, *C* is the scale factor for *x*. *C* is also the
coefficient of *x*, and may be called the constant of proportionality of
*y* to *x*.
*Geometry*:
The ratio of any two corresponding lengths in two similar geometric
figures. The ratio of areas of two similar figures is the square
of the scale factor.
→ *scale*; → *factor*. |

کروند ِ مالش ِ استوکس karvand-e mâleš-e Stokes
*Fr.: facteur de friction de Stokes*
For the translational motion of a spherical body moving in a
→ *viscous fluid*, the proportionality
factor between the uniform flow velocity far from the sphere and
the drag force, provided no-slip boundary condition and small
→ *Reynolds number*s:
*f* = 6πη*R*, where
η is the Reynolds number and *R* radius of the sphere. → *Stokes*; → *friction*;
→ *factor*. |