bu̍t-lí-ha̍k, la̍t-tiûⁿ (force field) sī 1 ê hiòng-liōng-tiûⁿ (vector field), ēng lâi piáu-sī ūi-lêng (potential) ê kai-tō͘ (gradient). La̍t-tiûⁿ lāi-té múi 1 tiám ê hiòng-liōng tō sī tī hit tiám ê la̍t, ē-tit ēng N lâi piáu-sī.

Chit-liōng, tiān-hō, khip-thih piⁿ--á ê khong-kan ē ū la̍t-tiûⁿ tī-leh, mi̍h-kiāⁿ nā tī hit lāi-té, tō ē kám-kak ū la̍t teh kā sak.

Le̍k-tiûⁿ ê lē

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