Do the Dew, geek style.

From: ari@obfgvp.pbz
Date: Thu, 27 Aug 1998 08:05:00 -0400 (EDT)
Message-Id: <199808271205.VNN04613@zbatbbfr.ofqv.pbz>
To: ari@obfgvp.pbz (/dev/null)
Subject: Do the Dew.

Forwarded-by: "Christophe 'Z' Kalt" <xnyg@erfrnepu.oryy-ynof.pbz>
From: Cliff Miller <poz@erfrnepu.oryy-ynof.pbz>

i actually spent an hour figuring out the formula for how fast you can
drive around a corner without tipping over your mountain dew.  it is:

	v = sqrt( g * r * (d/2) / z(f) )
and:
	z(f) = h/2 * (c + f^2 * s) / (c + f * s)
where:
	g = gravity (10 m/s^2)
	d = diameter of can (64 mm)
	r = radius of curvature of driving path
	z(f) = height of center of gravity of can,
		as a function of how full it is
	h = height of can (123 mm)
	c = weight of empty can (15 g)
	s = weight of 12 oz. of soda (355 g)
	f = fullness of can (1=full, 0=empty)

some facts:

- estimating a tight corner to have radius about 10 m (30 ft),
	the fastest you can go around it without spilling
	your (full) soda is about 16 mph.
- the optimum fullness of the can (i.e., when it has its
	lowest center of gravity and thus is least likely
	to spill) is 21%.  if your mountain dew were only
	this full, you could go 71% faster around any corner
	without spilling (which is good because by that
	time you want to go faster).
- on the other hand, if they made 8 oz. mountain dews,
	you could go 22% faster with a full 8 oz. can than
	with a full 12 oz. can.
- this could also be applied to beer, but i believe beer
	is lighter-weight than mountain dew because of
	the higher carbonation -- with the result that
	you have to go slower around corners with beer
	(but only if you've drunk some -- the speed limit
	is the same if the can is full).

i bring this up because periodically i do spill mountain dew in the car
(there's a nice spot right next to the parking brake to put it, but no
guard to keep it from tipping), and i keep wishing there were an extra
indicator on the speedometer that would also read the sharpness of my turn
and compute the "spill speed" (of course i suppose i would need a
"dewometer" so that the fullness of the can could be measured and factored
in).

other solutions to the problem:

- drink motor oil (it's heavier, so you can go faster around
	corners without spilling)
- pour mountain dew on the surface where the can sits so that
	it will get sticky; the can will stick to the surface
	and not spill.
- VELCRO mountain dew!!!  (how's that for a marketing idea?!?)
- drive over the sidewalk at those corners (this would reduce
	the sharpness of the turn and thus allow you to go faster)

and here's the formula for how empty the can needs to be before i can
screech the tires around corners without spilling:

	f = sqrt[ (d*s/u)^2 - 4*h*s*c*(h-(d/u)) ]  /  (2*h*s)

where h,d,s,c are as above, and u is the coefficient of friction between
tires and road (the ratio of the weight of the car to the force needed to
push the car sideways).  unfortunately i can't push my car sideways hard
enough right now to compute this ratio, probably because i haven't had
enough mountain dew yet.

-cbm
--
CLIFF MILLER (poz@erfrnepu.oryy-ynof.pbz)  908-582-6450.  Office MH
2C-415.