State the SI and CGS units of G.

Explanation

(i) According to newton's law of gravitation,
`F=(Gm_1m_2)/(r^2)`
`therefore G=(Fr^2)/(m_1m_2) " "….(i)`
(ii) In SI system, force is measured in newton (N), distance is measured in metre (m) and mass is measured in kilogram (kg).
(iii) Substituting in equation (1) , we get , unit of G as
`("newton" xx ("metre")^2)/(kgxxkg)`
(iv) Thus , in SI system ,
Unit of G `=(Nm^2)/(kg^2) " or newton " m^2kg^(-2)`