既然重力是恒定的，我施加的力在大小上,不变，就是方向不同，无所谓我怎么移动;,答案总是,相同的。

Since gravity is a conservative force, and since my force is always the same in magnitude except in opposite direction, ; it doesn't matter how I move in; it will always come up with the same answer.

youdao

,速度改变了方向，但它的大小不变。

The velocities reverse directions, but the speeds remain the same.

youdao

另一项实验请参加者从白噪音（持续不变而不突显的噪音，如雨声——译注）中分辨出特定声音的方向。

Another test asked participants to work out the direction of specific sounds embedded within white noise.

youdao

At all future times, x proceeds as if nothing happened and then y, you are falling.

在此后的时间里 x 方向上的状态不变,而 y 方向上不断下落

耶鲁公开课 - 基础物理课程节选