Why cloud floats against the law of Gravity and does not come to the Earth?

Answer 1

- First, clouds are NOT gaseous: they are suspensions of tiny water droplets.
- Secondly, the mere pressure of the atmosphere would not suspend these droplets against gravity: pressure acts in all directions, and would not push them up. There are differences in pressure over large vertical distances, but this won't have any effect on a tiny droplet: the atmospheric pressure will not change significantly from one end of it to the other.
- The issue, as RickB stated, is the "stirring up" of the atmosphere. However, it is NOT the bouncing of the thermal energy itself that does this: that bouncing around is the same thing as the pressure. If this were the complete story, the water droplets would float a bit, but they would be exponentially more likely to be found near the ground than in the sky, because of the Boltzmann factor. So this cannot explain cloud flotation.

Important factors in this situation:
- It is because of the turbulence in the air, which stirs up MACROSCOPIC motions that are big enough to carry the droplets. This is, indeed, due to the solar input of energy (as RickB pointed out). However, it acts not just by providing non-zero temperature, but by powering convection currents that provide winds to give uplift.
- The other point is that when water droplets are carried downward by down-drafts, the air volume is reduced because of the increased pressure (air pressure is greater nearer the ground), so the temperature increases and the water evaporates into gaseous water vapor. So the cloud-stuff disappears!

Answer 2

This is an interesting question with an even more interesting answer...

Have you ever seen a rubber ball floating in a glass of water?
Then have you seen how the heavy iron nail simply sinks to the bottom?

Gravity is acting on both of them, then why does the nail sink while the ball floats?
What may be the reason for this?

Well, a simple analysis will give you the entity that makes this possible...
And the entity is the Buoyant force exerted by the fluid [water in this case]
All Liquids and gases are called fluids as they flow and they exert a buoyant force on anything that gets submerged inside them that has mass

↑Buoyant Force [B]
Body
↓Weight [mg]

The above free body diagram will easily make you realise that the Buoyant force that acts on the body and its weight are in opposite direcions

However the buoyant force Acting on the Ball is very large as compared to the nail and so it can easily balance the Earth's gravitational pull [weight]

This is beacuse the buoyant force is given by

B = Vdg

Where
"V" is the volume of fluid displaced [volume of the body]
"d" is the density of the fluid being considered
"g" is the acceleration due to gravity

Thus we can see that as the ball has low density [since rubber has low density] so it occupies a large volume
We can see that as the nail has high density [since iron has high density] so it occupies a small volume

As a result Buoyant force on the iron is lower and cannot balance the weight, that is why it sinks

Our atmosphere is made up of gases that are also fluids
These exert an upward buoyant force on any molecule

The Clouds are clusters of molecules of water and have a very low density [they are made of evaporated water molecules that have high energy and so remain as far away as possible to be able to move about freely] so the volume occupied by them is very high and so is the Buoyant force

So the buoyant force not only balances the weight but also dominates and pushes the clouds higher as a result of which they float

For further reading about Buoyant forces...refer

http://en.wikipedia.org/wiki/Buoyant_force

Hope that answers your question

Answer 3

Because they are only the gaseous substance they are not solid or liquid type that' s why they are lighter than air. So, due to which they do not fall to the earth. Now I ask you a question that why do not the moon fall on the earth as it is in the contact of the gravitational force of the earth and due to which it also come closer to the earth but then also it do not fall on the earth and the distance between the earth and it also do not decreases . (and the earth attracts every thing or particle with the same force ) it's answer is not that it is very massive or very heavy.
If you know the answer then do nothing and if you do not know this answer then ask it and then I will tell you the answer of this to the point and currect.

Answer 4

The short answer is: Because the thermal energy in the air continually "stirs things up."

When the sun shines, it adds energy to the earth which warms the air. This means all the air molecules bounce around very fast. They bounce around so fast that they are able to push apart from each other, even pushing so hard that they can push (light) things off the ground. This includes clouds.

If there were no sun to warm the air, the molecules of air (and water, in the clouds) would stop movings so fast and would quickly fall down to the earth's surface.

Answer 5

Clouds obey the laws of gravity but buoyancy is a better term, have you never noticed the flat bottoms of low clouds as they float on a layer of the atmosphere?

Answer 6

Due to atmospheric pressure which is greater than the gravitatinal pull exerted on the winds.