Raindrops?

[Carol Lowery]

OK my best friends granddaughter has a Dave Slayer question. Sera is 12 and extremely smart, but this one she has always wonder about. Sooooooooo Sera wants to know, and if anyone can give answers to this question.

How long does it take for a raindrop to hit the ground from a cloud?

 

[Caroline H]

I guess it would depend on how high up the cloud is

 

[Dave Slayer]

OK my best friends granddaughter has a Dave Slayer question. Sera is 12 and extremely smart, but this one she has always wonder about. Sooooooooo Sera wants to know, and if anyone can give answers to this question.

How long does it take for a raindrop to hit the ground from a cloud?

I think it depends on rain drop speed.

 

[Works4Him]

AWESOME awesome question. This could make for a great science lesson.

The first scientific principle at hand to consider is terminal velocity. In simple terms, terminal velocity is how fast an object can fall to the earth. I found a great website that talks about terminal velocity, and even computes the terminal velocity of different sized raindrops we find in nature, as well as explains why clouds float even though they're big blobs of raindrops. Here's that link.

So, if you assume you have a large raindrop, it reaches 20 miles per hour in it's journey to earth. The next thing you need to know is how high up a cloud is. This site lists the different types of clouds and their heights. According to this site, most rain clouds are around 6,000 feet up, or around a mile high.

So if a raindrop falls at a rate of 20 miles per hour, and it starts it's journey a mile up in the air you have a raindrop taking 1/20th of an hour to hit the ground, or in other words, about 3 minutes.

Of course, that's assuming a large raindrop and a typical rain cloud. Drizzle could take up to 45 minutes to hit the earth! As always, your mileage may vary.

 

[Works4Him]

If you wanted to give an advanced science lesson, you could also do the math to figure out the rate of acceleration of a raindrop, since the drop isn't going to start out at terminal velocity. But since I was just giving some fuzzy numbers anyway, it's not something that will totally throw off the rough figures I gave you.

 

[Vic C.]

I don't have the answer, but I did hear on a weather broadcast that raindrops aren't teardrop shaped.

Raindrops are Round...At First.

Raindrops start out as round high in the atmosphere as water collects on dust and smoke particles in clouds. But as raindrops fall, they lose their rounded shape. Instead, a raindrop is more like the top half of a hamburger bun. Flattened on the bottom and with a curved dome top, raindrops are anything but the classic tear shape. The reason is due to their speed falling through the atmosphere.

http://weather.about.com/od/cloudsandpr ... urgers.htm

 

[Carol Lowery]

Everybody thank you very much. Next school year this will make a great science project and I will tell my teachers. And your replies were very interesting. God Bless. Seralysa

 

[Jon-Marc]

OK my best friends granddaughter has a Dave Slayer question.

Please don't encourage him. That question is beyond my knowledge, but I've known a few people who know everything who could answer that question. :D