这意味着，当你向上加速时，当电梯加速时，弹簧上的读数会更大，你会感到沉重。

It means, when you are accelerating upwards, as the elevator picks up speed, the reading on the spring will be more and you will feel heavy.

youdao

于是我们知道，它会向上加速。

So we know that it's going to be accelerated uphill.

youdao

否则将无法向上加速,它向上加速。

Otherwise it would never be accelerated up and we know it will be accelerated up.

youdao

It means, when you are accelerating upwards, as the elevator picks up speed, the reading on the spring will be more and you will feel heavy.

也就是说当你向上做加速运动时,就像电梯加速的时候,弹簧的读数会增大,你会觉得自己变重了

耶鲁公开课 - 基础物理课程节选

Then you guys know, you just told me, acceleration is -9.8, We call it "minus" because it's accelerating down and up was taken to be the positive direction.

然后你们都知道,你告诉我,加速度是-9.8,我们取负号是因为加速度方向朝下,而正方向为竖直向上

耶鲁公开课 - 基础物理课程节选

Now, what happens if the elevator is accelerating upwards with an acceleration a?

现在如果电梯向上以加速度 a 运动,会发生什么呢

耶鲁公开课 - 基础物理课程节选