Question

If all physical bodies attract each other with the force of gravity, then why do they not collide with one another?

Answer 1

Hey!

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We know that all bodies do attract each other because of force of gravity, but we don't collide with each other.

The reason is, the force of attraction isn't that high, it's very low that's the reason we don't collide with each other, but we do attract each other , just the thing is force of attraction is very weak.

We know,

F = G m1 m2 / r^2

F = Force of attraction
G = Gravitational Constant
M1 = Mass of on object
M2 = Mass of another object
R = Distance between them

Let , there be two books of mass 5 kg and 6kg kept at a distance of 1 m, let's see what's the force of attraction,

F = 6.67×10^-11 × 5×6
F = 200.1 × 10^-11

See, force of attraction is too less, but they do attract each other , no matter if they touch each other or not.


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Hope it helps...!!!

Answer 2

Your Question eventually mean that, Why Gravity is the weakest force of all other forces?
I can understand on small scale ( within an atom / molecules) . The other forces are much stronger than gravity but on the large scale, it seems the gravity is stronger than all forces.
We can say that gravity is much weaker than the forces , we mean that its Coupling Constant is much smaller than the Coupling Constant of the other forces .
To observe it, Simply , The gravitational force is the weakest force as its Coupling Constant is small in value.
Another is universe have no negative mass that have same value of Electromagnetic force.

On the basis of this, gravity is weakest of all forces because :

1) Unlike other forces, which is short ranges , it stretches into large distance and hence weak.
2) There is nothing like negative mass to behave like short distance and much stronger because how much short is Force, how much strong, it is .
3) Unlike , other forces, which is governed by particles which some properties . The gravity is a huge curve of the Space-time . Some physicist say it is governed by Graviton.
4) It is weakest due to low value of Coupling Constant .

There are some explanation that make gravitational Constant too small and Gravity weakest .