Question

What do you understand by the term “force of gravity”?

Answer 1

Hint: To solve this question we at first need to understand what actually gravity is and what type of characteristics it exhibits. By which unit it is represented and how is it represented mathematically.

Formula used:
${{F}_{g}}=\dfrac{G{{m}_{1}}{{m}_{2}}}{{{r}^{2}}}$

Complete answer:
We must understand that in this universe, there are a lot of forces. An object unknowingly always tends to push or pull some other object. There are four fundamental forces from which each and every other force is derived: weak force, gravitational force, strong force and the electromagnetic force.

So, as we know, gravity is actually the force with which Earth tends to attract a mass towards itself.
We can also say that gravitational force is a force by virtue of which any body with mass attracts another body which has mass. This force always tends to pull two or more masses together; this force never pushes any object away.

This phenomenon can be understood by Newton's universal law of gravitation.
It can be mathematically represented by the equation,
${{F}_{g}}=\dfrac{G{{m}_{1}}{{m}_{2}}}{{{r}^{2}}}$.

Where $F_g$ is the force of gravitational attraction, $m_1$ and $m_2$ are the 2 masses and r is the distance between their centres.
G is the universal gravitational constant = 6.67 $\times$ 10$^{-11}$ Nm$^{2}$kg$^{-2}$
The unit of gravitational force is Newton(N).

Few examples where gravity is exhibited is,
- The gases in the sun are held together with the help of this gravitational force.
- This gravity is responsible for water to be rested at the bottom of a glass instead of hovering anywhere.
- This gravitational force is the reason for the cause of tides in the ocean. Due to gravity there is a force of attraction between the moon and the earth that is the reason for tides.

Note:
Electromagnetic force is given by Coulomb's law which is analogous to the gravitational formula where the mass is replaced by charge.