Question

State and explain Universal law of Gravitation. Give its vector form.

Answer 1

• Law of gravitation-

According to this law, any two body at some distance having mass will feel an attraction force, this law is universal because it is applicable to any body in universe having mass.

If two bodies having mass $m_1$ and $m_2$ are at a distance $r$ any time then the force of gravitation $F$ is given as $F=\frac{G{m}_1{m}_2}{r^2}$

its vector form is like this $\overrightarrow{F}=\frac{-G{m}_1{m}_2}{r^3}\overrightarrow{r}$

The minus sign denote that its force of attraction that is opposite to distance vector $\overrightarrow{r}$ from one mass to second mass .

$G$ is universal gravitational constant having value $6.7\times {10}^{-11}$ in $M.K.S.$ unit.