Euler's equations of motion

例句：

1. 1. Theequations describe the motion of a particle in a given field.
   这些方程描述了粒子在给定场中的运动。
2. 2. The study of these equations is crucial for understanding the behavior of fluids.
   研究这些方程对于理解流体的行为至关重要。
3. 3.The equations are used to calculate the trajectory of a projectile launched from a point.
   这些方程用于计算从一点发射的弹丸的轨迹。