It's the basic physics that the air is thinner and the resistance to any projectile is less so the flight path of the ball will be different at high altitude.

基本物理学理论上，空气越稀薄情况下，任何物体的耐性都会减少，因此球路也会因海拔高度不同而有所变化。

youdao

External Ballistics deals with projectile flight. The trajectory, or path, of a projectile is subject to the forces of gravity (see gravitation), drag, and lift.

外弹道学是研究射弹的飞行，弹道是射弹在重力、拖曳力和升力作用下的飞行路线。

youdao