Question

Define universal gravitational constant.

Answer 1

Gravitational constant:

1. The gravitational force between the bodies of unit mass each separated by a unit distance is known as the universal gravitational constant $\left(G\right)$.

2. According to Newton's universal law of gravitation, $F=\frac{G{m}_1{m}_2}{r^2}$

where, $F\to$gravitational force

$G\to$universal gravitational constant

$m_1$$\to$mass of body 1

$m_2$$\to$mass of body 2

$r\to$distance between body 1 and body 2

3. So as per the definition, when $m_1$=$m_2$=$1kg$ and $r$= $1m$ then $F=G$.

4. The value of $G=6.67\times {10}^{-11}\frac{N{m}^2}{k{g}^2}$everywhere in the universe.

5. The value of $G$ is a universal constant. It remains the same everywhere irrespective of the location.

6. Because of small value of $G$, gravitational forces are the weakest forces in nature.