So the Pentagon awarded a 4-billion-dollar contract to build a version with a lower center of gravity and improved suspension.

VOA: standard.2010.08.01

It violates gravity, but six-month-olds aren't smart enough to know that a block just stuck over here is also surprising.

因为它违背了地心引力,但六个月大的婴儿还是不够聪明,他们没能发觉突出的木块也是令人惊奇的

耶鲁公开课 - 心理学导论课程节选

It knows that this particle happened to have a height of 15, at the time of 0, and a velocity of 10, and it is falling under gravity with an acceleration of -10.

这个质点恰好处在高度为15的地方,零时刻,初速为10,并在重力作用下以-10的加速度下坠

耶鲁公开课 - 基础物理课程节选

I mean all those of you doing sports here-- and it's most of you in this room who are doing athletics, who go for a run, you rely on the law of gravity.

你们中喜欢运动的-,教室里多数人都做运动，跑步时需要万有引力定律。

哈佛公开课 - 幸福课课程节选

And reality-- there's Law of Gravity.

现实就是万有引力的存在。

哈佛公开课 - 幸福课课程节选

For example, suppose you use vertical motion and you use y instead of x; and a would be g or -g; that's a particle falling down under the affect of gravity.

例如,假设在竖直运动中,你用 y 来代替 x,那么 a 就是 g 或者 -g,这就是一个受重力作用下落的质点

耶鲁公开课 - 基础物理课程节选