bu̍t-lí-ha̍k, tín-tāng (eng. motion) ia̍h ūn-tōng (ji̍t. 運動) sī chi̍t hāng bu̍t-thé keng-kòe sî-kan hoat-seng ê ūi-tì kái-piàn. Ūn-tōng ē-tàng ēng ōaⁿ-ūi (displacement), kū-lî (distance), sok-tō͘ (velocity), ka-sok-tō͘, sî-kan kap sok-le̍k (speed) chiá ê sêng-hun lâi kì-su̍t.