Rain love

Rain is probably the most captivating of the natural phenomena. Wet in the rain is one of the most beautiful feelings. Almost everyone throws raindrops out of the window. But how many have bothered with the speed of this raindrop?

Medium-sized clouds live an average of 6 km above the ground. When raindrops fall under the influence of gravity from such a height, their speed is about 398 meters per second when they reach the surface. It will be clear if we give an example of how fast and terrible this speed is. Where the speed of a normal rifle bullet starts from 160 meters per second, the speed of a raindrop is 396 meters per second! The raindrops were supposed to fall at such a high speed (I'll tell you later what would have happened), but in reality it didn't. The main reason for not reading so fast is the viscosity.

Viscosity is a measure of the extent to which a fluid (such as liquid or air) is obstructed. Just as friction interferes with the relative motion of two solids, so does viscosity interfere with the relative motion of two layers of fluid and try to disrupt motion. Although the friction force does not depend, the value of the viscosity ball depends on the area of ​​the two flow layers. This is why viscosity forces work better in relatively large droplets. However, due to the large size of the drop also increases the weight. As a result, the net velocity of the raindrop increases.

Again, it is easy to see from Stokes' law of viscosity that the resisting force on an object is proportional to its velocity. That is, if a viscous current, such as a sphere such as a drop of rain, falls through the air under the influence of gravity, its velocity will initially increase due to the gravitational acceleration and at the same time the barrier force on it will increase, thus reducing the net acceleration of the raindrop. At some point the net acceleration will be zero and the drop will fall to the ground with constant velocity. This velocity, however, is known as the ultimate velocity in various books.

This means that the speed at which the raindrops fall will no longer depend on the height of the clouds. Rather it depends on its size. Most of the water droplets that fall during moderate rainfall (which is said to be comfortable) have a radius of .25 to 1.25 millimeters. Now without diagonal wind flow, using the concept of ultimate velocity and various equations related to viscosity, it can be shown that a raindrop with a radius of .5 mm will fall to the ground at a speed of about 30 m per second.

That is, it is seen that rain does not fall at a speed of 398 m / s. Rather it falls at a speed which creates a wonderful rhythm in the tin rice; Love awakens the human mind. Everyone, especially teenagers, is so keen on getting wet in the rain because of this moderate speed of raindrops.

When the baridhara spreads all over the body through the cheeks during the veggie, I can't describe the wonderful shiver that rocks the body. And without this viscosity the rice in the house might have easily decayed in the rain; The melodious sound of rain would then turn into noise pollution.

The couple and the couple could not enjoy the wonderful pleasure of Vega in the rain holding each other's hands. It can be said with closed eyes that without the viscosity, the word rain love would not have originated, there would not have been hundreds of favorite songs whose focus was on rain. So many poets might not have written a poem about rain and love, but the poet Sukanta might have written a poem of hardship by finding the similarity of rain with the bombing during the Second World War.

As much as hail is harmful and unwanted to us, our favorite rain would be just as unnecessary and unwanted if there were no viscosity.