Question

justify the need of gravitational force

Answer 1

It keeps the Universe growing for one, it also acts as an organisational force in the development of all planets in space. Of course gravitational force is what keeps us stuck to the floor we walk on too. ... It's actually on that account, probably the most important force there is in existence.

Answer 2

I will be answering the question in two parts, as I have two different interpretations of the question.

PART 1:
If you are asking the question with respect to a school level course, then this part will provide you your answer.


In this part, I assume the question to be:
"What is the importance of Gravitational Force?"

Here's the answer:

# Gravitational Force is the weakest of the four fundamental forces of nature. However, it is always attractive, and this is what makes gravity important.

# In the early universe, there was only gas and dust. Due to gravitational force, the gas and dust came together to form clouds of gas and dust.

Moreover, these clouds collapsed to form stars. Also, planets were formed in the same way. Thus Gravitational Force is responsible for our very own existence.

# Gravitational Force is what keeps the planets in orbit around the sun

# Gravitational​ Force keeps us stuck to the Earth, otherwise we would have flown off. (We actually wouldn't have existed in the first place!)

_____________________________

PART 2:

If you asked this question out of curiosity, then this part is meant for that purpose only. In this part, I will go beyond the normal school course.

If I answered your actual question in the first part itself, then you may decide to skip this part.

In this part, I assume the question to be:
"Do we really need the concept of Gravity being a Force? "

Here's the answer:

Albert Einstein presented his General Theory of Relativity in 1915.

He showed that we don't need to think of gravity being a force.

In Relativity, the universe is made of four dimensional space-time (where time is the fourth dimension)

The presence of mass in space-time, distorts space-time, and causes it to curve.

Bodies always follow a straight line path in 4-D space-time. But when masses curve space-time, other smaller masses moving through that place follow a curved path, called geodesic.

Consider an example: The Earth, being very massive, curves space-time around it. Now, there's the moon nearby. The moon is actually following a straight line, but due to curvature due to earth, it's path appears to be curved around earth.

This gives the appearance that moon is orbiting the Earth.

I have attached a representational figure.

So, we don't really need the concept of gravity being a force.

If you want some more examples, here's a question I answered some time back:

https://brainly.in/question/1207013