instantaneous linear velocity meaning in Chinese

瞬时线速度

Vibration of tank gun in the process of firing is one of the main factors that affect its firing accuracy , especially the instantaneous angular motion and the instantaneous linear velocity at the point of gun muzzle when the projectile leaves the barrel bore
影响坦克炮射击精度的主要因素之一是火炮振动，起关键作用的振动分量是在弹丸出炮口瞬间炮口振动角位移和横向线速度。