From Fr., from Gk. elastos "ductile, flexible," related to elaunein "to strike, beat out."
Kešâyand, from keš stem of kešidan/kašidan "to pull, drag, draw" (Av. karš- "to draw, to plough," karša- "furrow;" cf. Skt. kars-, kársati "to pull, drag, plough," Gk. pelo, pelomai "to be busy, to bustle") + âyand agent form of âmadan "to come; to become," from Mid.Pers. âmatan (O.Pers. gam- "to come; to go," Av. gam- "to come; to go," jamaiti "goes;" O.Iranian *āgmatani; Skt. gamati "goes;" Gk. bainein "to go, walk, step;" L. venire "to come;" Tocharian A käm- "to come;" O.H.G. queman "to come;" E. come; PIE root *gwem- "to go, come").
Fr.: collision élastique
A collision between two particles which conserves the total kinetic energy and momentum of the system.
Fr.: déformation élastique
Fr.: limite d'élasticité, ~ élastique
Fr.: diffusion élastique
In a → collision between two → particles,
the reaction in which the total → kinetic energy
of the system, projectile plus target, is the same before the collision as after.
mowj-e kešâyand (#)
Fr.: onde élatique
A wave that propagates by → elastic deformation of the medium. The → propagation takes place by a change in shape that disappears when the forces are removed. In other words, the displaced particles transfer momentum to adjoining particles, and are themselves restored to their original position. A → seismic wave is a type of elastic wave.
The ability of a body which has been → deformed by an applied → force to return to its original shape when the force is removed. Up to a certain point the material obeys → Hooke's law. See also → ductility, → plasticity.
Fr.: collision inélastique
A collision between bodies in which there is a loss of total kinetic energy.
Fr.: diffusion inélastique