例子
功
功取決於位移和作用在物體上的力。當質點沿路徑C在力場中運動時,力做功為曲線積分:
對保守場來說,它也與路徑本身無關,只取決於始終點。因此,在起點與終點重合的閉合路徑上運動的物體的功為0:
認識到保守向量場可以寫成某個純量勢函數的梯度,可以更容易地評估所做的功:
功就是起點和終點的電勢值之差。如果這兩個點分別為x = a、x = b,則:
另見
參考文獻
外部連結
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