# The Naked Scientists Forum

### Author Topic: how fast does rain fall?  (Read 7690 times)

#### paul.fr

• Guest
##### how fast does rain fall?
« on: 07/06/2007 10:20:31 »
assuming there is no wind to make it go faster, how fast does rain fall?

#### DoctorBeaver

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• A stitch in time would have confused Einstein.
##### how fast does rain fall?
« Reply #1 on: 07/06/2007 11:25:56 »
If rain were to fall vertically, it would accelerate at 1g. You can work out the speed it would reach falling from different altitudes because I can't be bothered to.

Of course, you'd have to take into account wind speed, updraughts, air resistance etc to get an accurate answer.

#### Bored chemist

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##### how fast does rain fall?
« Reply #2 on: 07/06/2007 20:02:29 »
I think you need the Stokes Einstien equation.
The terminal velocity of raindrops is pretty small- it depends on the size. Ignoring air resistance for a drop falling from a cloud would give a totally misleading answer so I won't bother either. Also this site
http://www.grow.arizona.edu/Grow--GrowResources.php?ResourceId=146
calculates it in a nice cute manner and does take drag into account.

#### DoctorBeaver

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##### how fast does rain fall?
« Reply #3 on: 07/06/2007 20:04:35 »
Interesting little site

#### paul.fr

• Guest
##### how fast does rain fall?
« Reply #4 on: 07/06/2007 20:08:00 »
I think you need the Stokes Einstien equation.
The terminal velocity of raindrops is pretty small- it depends on the size. Ignoring air resistance for a drop falling from a cloud would give a totally misleading answer so I won't bother either. Also this site
http://www.grow.arizona.edu/Grow--GrowResources.php?ResourceId=146
calculates it in a nice cute manner and does take drag into account.

excellent, thanks BC

#### The Naked Scientists Forum

##### how fast does rain fall?
« Reply #4 on: 07/06/2007 20:08:00 »