作者: 阮一峰

日期: 2006年8月 7日


Projectile是指抛射出去的一个物体,尤指炮弹。(a weapon that is forcibly thrown or projected at a targets but is not self-propelled. 英语释义皆取自WordNET,以下同。)

Trajectory指的是抛射出去的物体的运行轨迹,比如弹道就是ballistic trajectory。(the path followed by an object moving through space.)

Parabola是数学中的抛物线,是技术名词,用数学语言说,就是具有ax^2+bx+c(a<>0)形式的曲线,在几何上就是一个平面切割圆锥体所产生的交集。形容词形式是parabolic,它同时也是parable(寓言) 的形容词形式。(a plane curve formed by the intersection of a right circular cone and a plane parallel to an element of the curve )


* Without air resistance, the projectile will follow a parabolic trajectory.

* The trajectory of the projectile is known to be a parabola.

* any trajectory taken by a projectile is a parabola.