whaley (01/17/83)
#N:uiucdcs:24400024:000:373 uiucdcs!whaley Jan 16 20:36:00 1983 I am wondering if any of you have opinions on the following question which I used to wonder about when I was younger but have yet to solve. The problem is this: does one get wetter when runs through a rainstorm or when walks. I imagine it depends on lots of things; what do you think? (Maybe this will replace tea and cream!) Al Whaley Univ of Ill pur-ee!uiucdcs!whaley
CSvax:Pucc-H:Physics:retief (01/18/83)
I've worked out the problem before and assuming that there is no
violent wind whipping the rain in ALL directions then:
1) If you DON'T have an umbrella, you should run as fast
as you can through the rain (you'll get wet on your front
but I assume you don't care.
2) If you DO have an umbrella, you should walk slowly and
angle the umbrella along the angle of the rain.
3) To INTERCEPT the minimum amount of rain all you need do
is run at the speed of light. No problem.
D.U.B.franka (01/21/83)
#R:uiucdcs:24400024:tekcad:11200001:000:306
tekcad!franka Jan 21 12:20:00 1983
The obvious response to the rain question is c) None of the above.
The fool should use an umbrella.
Proud to live where we can do first hand
research on rain!
Frank Adrian
uucp: {ucbvax,decvax,chico,pur-ee,cbosg,ihnss}!teklabs!tekcad!franka
CSnet: franka@tek
ARPAnet: franka.tek@rand-relayjohnl (01/22/83)
#R:uiucdcs:24400024:ima:18700001:000:179 ima!johnl Jan 21 12:19:00 1983 I always thought the preferred strategy was to run because then you got home sooner. (Sorry, gang.) John Levine, decvax!yale-co!jrl, ucbvax!cbosgd!ima!johnl, research!ima!johnl
faunt (01/24/83)
No-one has yet taken into account a real-world fact, that the faster you move, the shorter the time you will be exposed to the rain, although the "answers" I've seen at this time indicate that moving as fast as possible is best, which would also minimize exposure time.
bernie (01/25/83)
It seems obvious when you think about it :
when you run, you will get hit with some number of raindrops X.
Assuming it's a fairly short distance, you will not be thoroughly
soaked.
if you run more slowly, you'll get wetter. (consider the extreme case
of not moving at all; you will be soaked to the skin if you just wait
long enough).
Therefore it is far better to run through the rain, the faster the
better. Unless, of course, you slip and fall into a puddle...
(does this qualify as an experimental error?)
--Bernie Roehlal (01/28/83)
In regard to: From decvax!harpo!seismo!hao!hplabs!faunt Sun Jan 23 20:52:45 1983 Subject: Re: strategy in rainstorms - (nf) Newsgroups: net.physics No-one has yet taken into account a real-world fact, that the faster you move, the shorter the time you will be exposed to the rain, although the "answers" I've seen at this time indicate that moving as fast as possible is best, which would also minimize exposure time. It is not true that the length of time is not taken into account. In both the spherical body analysis someone else submitted and my rectangular body analysis, the length of time is very much taken into account. The fact that you have to get to a particular place (in the horizontal direction) and that you are moving with constant velocity in the vertical direction (a transfor- mation of the rain's actual falling down) means that if you stood still, you would get infinitely wet since you never reach your goal and yet you are still moving vertically and intercepting all those raindrops.
mmt (01/28/83)
You can imagine your body sweeping out a volume of space in the rainstorm. If you stay in the rain for a time T, you will sweep out ATv cubic whatevers (A is the area you present to the rain, v the velocity you have relative to the rain) and all the rain in this volume will hit you. If you stay in the rain for a fixed time, it is best to stand still, or at least move at the speed of the wind, so that v is only the vertical velocity of the rain and A consists of your head and shoulders. If you need to go a certain distance, and do it very fast, Tv is essentially independent of your running speed, since v is dominated by your speed. But as your speed increases, so does A, the area you present to the rain (unless you lean very far forward, so that you still present your head and shoulders to the rain -- ie lean exactly as much as the perceived slant of the rain). At intermediate speeds, v includes components from both your velocity and that of the rain. Best to take an umbrella. I haven't worked it out, but there may be an optimum running rate for any particular trip in the rain. Maybe fastest is best if you can do it on your stomach. Martin Taylor
Scott@SRI-AI (02/05/83)
From: Scott J. Kramer <Scott @ SRI-AI>
Date: 23 Jan 83 20:52:45-PST (Sun)
From: hplabs!faunt (Doug Faunt) at Berkeley.arpa
To: physics at sri-unix
Re: strategy in rainstorms - (nf)
Return-path: <@MIT-MC,@sri-unix:knutsen@Usenet>
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No-one has yet taken into account a real-world fact,
that the faster you move, the shorter the time you will be
exposed to the rain, although the "answers" I've seen
at this time indicate that moving as fast as possible is best,
which would also minimize exposure time.
This is my driving philosophy... the faster you drive, the less time
you're on the road and therefore your chances of having an accident
are less.
scott