Question

The value of gravitational constant, $G$ is

• A. $9.8m{s}^{-2}$
• B. $6.7N$
• C. $6.7\times {10}^{-11}N{m}^{2}k{g}^{-2}$
• D. $6.7\times {10}^{-11}N{m}^{2}k{g}^2$

Answer 1

The correct option is C

$6.7\times {10}^{-11}N{m}^{2}k{g}^{-2}$

$G$ is universal gravitational constant. Its value remains constant everywhere in the universe and gravitational force between bodies $m$ and $M$ separated by distance $r$ is given by:
$F=\frac{GMm}{r^2}$
$\Rightarrow G=\frac{F{r}^2}{Mm}$
$\therefore$ Units of G are $N{m}^{2}k{g}^{-2}$
The value of Gravitational constant is $6.7\times {10}^{-11}N{m}^{2}k{g}^{-2}$.