Culeyska Waa awooda jiidashada ee dhulka, waxaana ogaaday aqoonyahakii Isxaaq Niyuton waxaana lagu cadeeyey Buuga lagumagacaabo Philosophiæ Naturalis Principia Mathematica F → = m g → {\displaystyle {\vec {F}}=m\,{\vec {g}}} g Waa Cuf isjiidka g = F m = G M T R T 2 {\displaystyle g={\frac {F}{m}}={\frac {GM_{T}}{{R_{T}}^{2}}}} Tusaale ahaan Haddii ay Cufnaanta walaxi tahay 200 Garaam, Cuf isjiidka waxa uu noqonayaa 2 Niyuton oo macnaheedu tahay Culeys ka. Haddii ay tahay Cufnaanta Walaxi 1000 Garaam oo ah 1kg, Cuf isjiidka dhulka waxa uu noqonayaa 10 Niyuton, Oo macnaheedu yahay 1kg dhulka guudkiis waa 10 Niyuuton. F = G M T m R T 2 {\displaystyle F={\frac {GM_{T}m}{{R_{T}}^{2}}}} = 6,674 ⋅ 10 − 11   N m 2 k g − 2 ⋅ 5,974 ⋅ 10 24   k g ⋅ 1   k g ( 6,373 ⋅ 10 6   m ) 2