Perfectly plastic collision

…Generally, the degree of repulsion is expressed by the ratio of the relative velocities before and after (the negative sign is used because the direction of v ₁ - v ₂ and the direction of v ₁ ' - v ₂ ' are opposite directions). e is called the coefficient of restitution, and e = 1 is a perfectly elastic collision, 0 < e < 1 is an inelastic collision, and e = 0 is called a perfectly plastic collision or a perfectly inelastic collision. When e < 1, the energy of the relative motion is converted into the internal energy (thermal energy) of the ball after the collision. …

*Some of the terminology explanations that refer to "fully plastic collision" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…一般には，これら前後の相対速度の比をもって反発の度合を表す(負号をつけるのはv₁－v₂の方向とv₁′－v₂′の方向が反対方向のため)。eを反発係数coefficient of restitutionといい，e＝1が完全弾性衝突，0＜e＜1が非弾性衝突であり，e＝0は完全塑性衝突，または完全非弾性衝突と呼ばれる。e＜1の場合は相対運動のエネルギーは衝突後球の内部エネルギー(熱エネルギー)に変換される。…

※「完全塑性衝突」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報