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why the rain drops are singlely fall from the sky,there have on net in the sky?

why the rain drops are singlely fall from the sky,there have on net in the sky?
 

Grade:12

2 Answers

Sourabh Singh IIT Patna
askIITians Faculty 2104 Points
7 years ago
Hii your question is not clear .Kindly repost the questionand we will get back to you.
jyoti bhatia
202 Points
7 years ago
The description, “zillions of tiny droplets of water floating in air”, applies to every fog, to every mist, to every burst of stream and to every cloud in the sky. When a cloud grows, water vapour in the air gradually ‘condenses’ to form lots more tiny droplets. When a cloud shrinks, many droplets are completely ‘evaporating’ to become invisible water vapour.
As winds move air across the sky, carrying clouds along, fragments of wind called ‘eddys’ can do strange things to shapes of clouds. Also, winds from different directions can collide with each other which has great effect on clouds. It depends on how cold or warm the colliding winds are and how much water each wind carries (only differences matter, not whether water is in form of vapour or tiny drops).
For rain to happen, weather conditions inside and outside the clouds has to cause droplets to grow. Some droplets will grow by colliding and combining with each other. Some droplets will grow by acquiring more water vapour from air. Some will do both. MOST of the droplets in clouds grow at the same time.
BUT, droplets do not grow at the same rate; some grow faster than others. As soon as ANY get big enough, they start to fall out of the cloud. Water is heavier than air, after all. Depending on wind conditions, those first raindrops may be blown back up into the cloud, where they can grow some more. Eventually, they get too big to stay up in air, so they fall all the way to ground. Slower-growing droplets will fall after them and slower-growing-yet droplets will fall after THEM, and so on. This is the essence of raining process.
There are a couple of reasons why raindrops don’t combine to make a single stream. First reason is simple that raindrops start falling just as soon as they are too heavy to stay in the air. Second reason is that they are all falling together DOWNWARDS, not sideways. If wind blows them sideways, they all move TOGETHER sideways. That is not good enough to cause them to meet each other, while falling, so they could combine to form a single stream.
Finally, there is one more reason which only partly applies. THIS reason applies to existing streams of water which move through the air and causes them to break up into droplets. In other words, if rain DID happen to fall out of the sky in a stream, this reason would turn it into raindrops!
Two phenomena work together to create that reason. They are ‘surface tension’ and ‘air resistance’. When a stream of water moves through air, it encounters resistance that deforms the shape of stream. This HELPS the property of water known as surface tension to create droplets. So, the stream breaks apart. The farther through the air the water moves and the more air resistance it encounters, the more it can break into droplets. If initial stream of water fell thousands of feet from clouds to the ground, it would become completely broken up into a pretty ordinary rainfall.
One of the wonders God created in rain is that rain does not fall onto ground in form of large water mass like waterfalls. If rain fell on the ground in this form, it would not be possible for people to continue their daily lives during rainy seasons and floods would form during every rainfall. These floods would cause serious damage, both material and spiritual. However, due to laws of physics, it falls on ground in drops and be decreasing its speed turns into precious water which is source of life for all beings.
Reason that rain falls in drops is that water droplets are formed inside clouds. A cloud is formed by water vapour being thickened with dust and electrically positive charged particles. Diameter of these particles is 1-10 microns (1 micron=0.001 mm). When clouds move upwards at certain speed (1-10 m/s), they take water droplets with them naturally. As water droplets rise up, they get bigger as their volume increases. Two or more droplets unite and form a raindrop. Air can no longer carry these drops and rain drops begin to fall on the ground.
Since big drops fall faster than small drops until they reach a fixed speed, big drops and small drops crash and unite. Drops, which get bigger through crashing & uniting, encounter air resistance which distorts shape of water drop, spreads and turns into many small droplets in a short time, on order of six hundredth of a second. Since speeds of drops of same size are same and they move in same direction, they do not crash with one another.   
 
 
 

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