Now, gravity, well force, is equal to mass times acceleration, g and the acceleration due to gravity is g.

是重力，等于质量乘以加速度，由重力导致的加速度是。

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Therefore, when you divide by the mass to get the acceleration, the response of different bodies is inverse to the mass.

因此,当你拿力除以质量得到加速度时,不同物体的加速度与质量成反比

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But the acceleration it produces on the elephant and on the mass, are in an inverse ratio of their masses.

但这个力使大象和物体产生的加速度,与它们的质量成反比

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One is inertial mass, which is how much you hate your velocity to change, how hard you resist acceleration.

一个是惯性质量,它反映了物体速度改变的难易程度,即保持加速度的难易程度

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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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If I pull the one kilogram mass and I let it go, it does something, some acceleration.

如果我拉 1 千克重的物体并松手,就会获得一个加速度

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And know intuitively that if they move together, they will behave like an object of mass 5 and the acceleration will again be 2.

凭直觉认为既然它们一起运动,那么它们就相当于一个质量为 5 千克的物体,然后我们可以算出加速度为 2

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So, when you divide by the mass to get the acceleration, you get the same answer.

因此,当等号两边除以质量来求加速度时,结果是相同的

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But this is the acceleration of the one kilogram mass.

但这是 1 千克物体具有的加速度

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Then, I bring the elephant and I pull the spring by the same amount and I find the acceleration of the elephant and the denominator is obviously the mass of the elephant.

然后我再找来大象,用相同的力去拉弹簧,大象就具有了加速度,很明显,分母就是大象的质量

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First one says, if you knew the force acting on any body, without going into what caused the force, then you may set that force equal the mass times acceleration of the body.

第一部分是,如果你知道作用在任一物体上的力,无论这个力的来源是什么,都可以令力等于质量乘以物体的加速度

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That's connected to mass times acceleration.

然后就能和质量乘以加速度联系上了

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You cannot say to me, "Take a force, due to a spring, and see what force it applies and divide by the acceleration and get the mass, " because we haven't defined force, either.

你不能说,"给弹簧施加一个力,看看它能提供多大的力,然后除以加速度,得到质量",因为我们还没给力下一个定义

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A typical problem that you may have done in your first pass at Newton's law, someone tells you a force of 36 Newtons is acting on a mass of whatever, 4 kilograms; what's the acceleration?

在你们第一次接触牛顿定律时,可能见过这么一道典型题目,告诉你,一个 36 牛的力,作用在一个物体上,4 千克吧,问加速度是多少

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We can be precise about how much bigger by saying, "If the acceleration of a body to a given force is ten times that of a one kilogram mass, then this mass is one-tenth of one kilogram."

我们能精确地知道质量能大多少,只需要说,"如果物体在给定力作用下的加速度,是一个 1 千克物体的加速度的 10 倍,那这个物体的质量就是 1 千克的十分之一"

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If your plan is to accelerate a 3 kg mass with an acceleration of 2 meters per second, you better have a rope that can furnish that force and it can take the tension of 6 Newtons.

如果你想用 2 米每秒平方的加速度,去拉一个 3 千克的物体,那么你就需要一根能提供拉力的绳子,并且它能够承受 6 牛的张力

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That's how by either balancing the unknown force with a known force or by simply measuring the acceleration as I fall towards this podium and multiplying by mass, you can find the force that exerts on me.

我们既可以让未知力与已知力平衡,也可以只测量我冲向讲台时加速度的大小,再与我的质量相乘,都能求出作用在我身上的力的大小

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