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The alternation of motion is ever proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed.
物体的加速度与所受的合外力成正比,与物体的质量成反比。加速度的方向与合力的方向相同。
The power of computation is not just in solving problems, but in the elegance and efficiency with which it does so.