Tiōng-le̍k

Tiōng-le̍k (Hàn: 重力; pe̍h-ōe-im: tāng-la̍t; Eng: gravitation, gravity) sī Bu̍t-lí-ha̍k ê iōng-sû, mā hō-chò bān-iú-ín-le̍k ia̍h bān-iú-ín-la̍t, sī kóng ū chit-liōng ê mi̍h-kiāⁿ ài beh sio oá ê chok-iōng. Tiōng-le̍k sī chū-jiân-kài 4 chióng ki-pún-la̍t ê 1 chióng, lēng-goā 3 chióng sī tiān-chû-la̍t, jio̍k-la̍t, ham kiông-la̍t; tiōng-le̍k sī chit lāi-té siōng sè, m̄-koh chok-iōng siōng hn̄g, koh tiāⁿ-tio̍h ū chok-iōng--ê. Kó͘-tiān le̍k-ha̍k kā tiōng-le̍k tòng-chò ū chit-liōng ê mi̍h-kiāⁿ sán-seng ê la̍t. It-poaⁿ siong-tùi-lūn kā tāng-la̍t tòng-chò ū chit-liōng ê mi̍h-kiāⁿ kā sî-khong oan-khiau liáu-aū ê chok-iōng, m̄ sī 1 chióng la̍t. Tī Liōng-chú tiōng-le̍k (quantum gravity) ê lí-lūn, ū lâng ká-siat ū tiōng-chú (graviton) thang thoân-pò tiōng-le̍k.

Tiōng-le̍k hō͘ he̍k-chheⁿ tī ka-tī ê kúi-tō se̍h Ji̍t-thaû. (bô chiàu pí-lē)

Newton kó͘-tiān le̍k-ha̍k ê tēng-gī

Jīm-hô nn̄g-ê ū chit-liōng (mass) ê bu̍t-thé tiong-kan, lóng ū chi̍t-ê hō·-siong khip-ín ê le̍k-liōng, chiū-sī tāng-le̍k.

Tiōng-le̍k kap bu̍t-thé ê chit-liōng ū ē-bīn ê koan-hē:

　　　$F={\frac {GMm}{r^{2}}}$

　　　${\begin{matrix}G=6.672\times 10^{-11}\quad N\ m^{2}\ kg^{-2}\\\ \ \ =6.672\times 10^{-8}\quad cm^{3}\ g^{-1}\ s^{-2}\end{matrix}}$

F sī nn̄g-ê bu̍t-thé chi-kan ê le̍k-liōng

G sī Bān-iú ín-le̍k siông-sò· (universal gravitational constant)

M kap m hun-pia̍t sī nn̄g-ê bu̍t-thé ê chit-liōng

r sī nn̄g-ê bu̍t-thé (M kap m) ê kī-lī