This is the force exerted by the spring on the mass.

这是弹簧对物体的作用力

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For example, how do I know that when I pull the spring the first time for the mass, it exerted the same force when I pulled the spring the second time for the elephant?

例如 怎样才能知道,第一次连着物体拉弹簧时,产生的力和,第二次连着大象拉弹簧时产生的力是相等的呢

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But if I'm accelerating, the force exerted by the spring and therefore, the needle the weighing machine reads is m.

但是如果我在加速运动,那么弹簧的弹力,也就是称重机上指针的读数就是 m

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