请帮忙翻译这个句子~~ 物理好的同学帮我解释解释~

问题描述:

请帮忙翻译这个句子~~ 物理好的同学帮我解释解释~
two-dimensional motion can result when the acceleration vector is not along the line of initial motion. in the horizontal projectile motion, the acceleration vector due to the gravity is initially perpendicular to its motion
这是一道物理题的答案。题目是:under what condition can you have two-dimensional motion with a one-dimensional acceleration?

题目是 在什么条件下,运动方向不沿加速度方向?
答案是 当加速度方向不在初始运动方向上时出现     例如在平抛运动中,偏离初始运动方向就是由于加速度开始时垂直于运动方向