free-fall test

例句：

1. 1. In the free-fall test, the object is dropped from a height and its motion is observed.
   在自由落体测试中，物体从一定高度自由下落并观察其运动。
2. 2. The free-fall test is used to measure the acceleration of an object during its free fall.
   自由落体测试用于测量物体自由下落时的加速度。
3. 3. During the free-fall test, the object's trajectory is recorded using a camera.
   在自由落体测试期间，使用摄像机记录物体的轨迹。