I draw a graph here of the amount by which I pull the spring versus the force it exerts.

我在这里画个图,纵轴是弹簧的拉伸量,横轴是力的大小

耶鲁公开课 - 基础物理课程节选

Newton is not going to come and tell you what force the spring will exert when it's pulled by some amount.

牛顿不会过来告诉你,弹簧被拉伸一定量时会产生多大的力

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We want to know how much force it exerts when I pull it by a certain amount.

我们想知道当我们将弹簧拉伸一定量时,它能产生多大的力

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Now I can measure that, because I pull it by one centimeter and I find the acceleration it exerts on a known mass.

现在就能测量这个力了,因为把弹簧拉伸 1 厘米,我就知道它让一个质量已知的物体产生的加速度

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Namely, if you pull it by so much, that's the force it will exert.

也就是,将弹簧拉伸这么长,它产生的力就有这么大

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You hook one end of the spring to a wall and you pull it from rest by some amount and you attach the one kilogram mass to it.

你把弹簧的一端固定在墙上,然后拉伸一段距离,接着你把 1 千克物体固定在上面

耶鲁公开课 - 基础物理课程节选