[net.misc] Zero G scale

solomon (05/29/82)

The zero-G scale problem reminds me of my favorite puzzle along these lines.
Practically anybody who's taken a high school physics course has seen
a problem along the lines of "how do you use a barometer to measure
the height of a building".  The usual answer is boring.  The interesting
puzzle is to think of IMMAGINATIVE answers.  Some examples:
	Climb up the side of the builing, using the barometer like a ruler
	Throw the barometer off the roof and time how long it takes
		to hit the pavement
I'll let you think of more.  Here's my favorite:
	Go to the building manager and say, "I'll give you this dandy
		barometer if you'll tell me how tall your building is."

-Marvin Solomon
(...!harpo!uwvax!solomon or solomon@uwisc)

doug (05/29/82)

here are some more I heard of:

(i)  go to the top of the building and lower the barometer with
     a string 'til it hits the sidewalk.  then pull the string 
     back up and measure it's length.

(ii) lower the barometer by a string again, and this time set it
     to swinging.  from the period of the simple harmonic motion
     you can find the length of the string.

(iii) stand the barometer next to the building and measure it's
      height and length of its shadow.  then measure the building's
      shadow and deduce its height from ratios.

there's one more beside the two Marv Solomon mentioned that I
recall was pretty funny, but I can't remember anything else about it.

doug@uwisc

pcmcgeer (05/31/82)

	Maybe this answer was the one you were thinking of:
(i) Drop the idiot barometer from the top of the building, and time its fall.
Then, from s = 4.9t**2, calculate the height of the building (in meters).
(ii) Weigh the barometer at the foot and the roof of the building.  Then
from the (minuscule) difference, deduce the difference r1**2 - r2**2, where
r1 is the distance from the centre of the earth to the roof of the building,
and r2 the distance from the earth to the floor of the building.  This will
give you a pretty good indication.(Actually, this is a not bad way to find the
value of G).

An objection can be made to either of these, or Doug's at U. Wisc., or Mr
Solomon's, on the basis that they all require another piece of equipment.  Ok,
here is one that answers those objections.  Measure the wind velocity (which
can be determined with a barometer and skill).  Launch the barometer.  The
wind gives it an intitial velocity, which in turn makes the fall a parabola.
Measuring its landfall from the side of the building gives you the height.

				Rick McGeer at UW
				watmath!pcmcgeer

laura (05/31/82)

The one I recall is -- Go to the building manager and say "If you dont tell
			me how tall this building is, I will smash this new
			barometer over your head".  Perhaps a little violent,
			but...

						laura creighton
						decvax!utzoo!laura

rogers (06/02/82)

  The way I had heard it was:   Go to the building manager and say "If
                                you tell me how tall this building is, I
                                will give you this nice barometer."