Calling all Einsteins

[ClubMed]

How could a barometer be used to determine the height of a tall building?

[Gibbo]

I presume it could be done by messuring the air pressure at ground level & at the top of the building in question.

Then dividing the difference by the average pressure/height difference (not sure what this is but something like - 5mb/10ft- you get the idea)

at least it sounds plausable to me at the mo

-edit-
mb = being millibars

[Graham]

Offer it to the concierge and........etc.


I thought that was Nils Bohr not Einstein.

G

[ClubMed]

Correct Gibbo

Here's what a bunch of school kids thought:

#1: Drop the barometer off the roof and time its fall to the street. Distance down = 16 feet x the number of seconds squared. Ex: 5-second drop = 400 feet.

#2: Lower the barometer on a long rope, then measure the rope.

#3: On a sunny day, compare shadow proportions. Ex: If the barometer's shadow is 5 times the barometer's length, then the building is 5 times as tall as its shadow is long.

#4: Count off barometer lengths to the roof as you climb the stairs, then multiply by the barometer's length.

#5: Knock on the building superintendent's door and say, "Hey, Mr. Super, I've got this cool barometer I'll give you if you tell me the height of this building..."

[Graham]

From

http://www.thehumorarchives.com/humor/0000899.html

Physics Exam

The following concerns a question in a physics degree exam at the University of Copenhagen:







"Describe how to determine the height of a skyscraper with a barometer."

One student replied:

"You tie a long piece of string to the neck of the barometer, then lower the barometer from the roof of the skyscraper to the ground. The length of the string plus the length of the barometer will equal the height of the building."

This highly original answer so incensed the examiner that the student was failed immediately. He appealed on the grounds that his answer was indisputably correct, and the university appointed an independent arbiter to decide the case. The arbiter judged that the answer was indeed correct, but did not display any noticeable knowledge of physics. To resolve the problem it was decided to call the student in and allow him six minutes in which to provide a verbal answer which showed at least a minimal familiarity with the basic principles of physics. For five minutes the student sat in silence, forehead creased in thought. The arbiter reminded him that time was running out, to which the student replied that he had several extremely relevant answers, but couldn't make up his mind which to use. On being advised to hurry up the student replied as follows:

"Firstly, you could take the barometer up to the roof of the skyscraper, drop it over the edge, and measure the time it takes to reach the ground. The height of the building can then be worked out from the formula H = 0.5g x t squared. But bad luck on the barometer.

"Or if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the skyscraper's shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the skyscraper.

"But if you wanted to be highly scientific about it, you could tie a short piece of string to the barometer and swing it like a pendulum, first at ground level and then on the roof of the skyscraper. The height is worked out by the difference in the gravitational restoring force T = 2 pi sqrroot (l/g).

"Or if the skyscraper has an outside emergency staircase, it would be easier to walk up it and mark off the height of the skyscraper in barometer lengths, then add them up.

"If you merely wanted to be boring and orthodox about it, of course, you could use the barometer to measure the air pressure on the roof of the skyscraper and on the ground, and convert the difference in millibars into feet to give the height of the building.

But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the janitor's door and say to him 'If you would like a nice new barometer, I will give you this one if you tell me the height of this skyscraper'."

The student was Nils Bohr, the only Dane to win the Nobel prize for Physics.


G

[ClubMed]

So after all it wasn't a bunch of students but the man himself ?

[Graham]

Bright lad by all accounts was Mr Bohr.

G

[Epidemic]

Knowing the physical constuction techniques and materials. One could assertain the velocity of the barometer on impact by the damage and the crater. From this one could determine the height of the building assuming that terminal velocity had not yet been reached prior to impact.

[OuTpaTienT]

I would assume it would hit terminal velocity. Plus it's doubtful that it'll leave any crater in the poured concrete it's most likely to impact.

[BFlurie]

They make "Altitude indicators" that are just barometers. They need to be calibrated in real-time to a nearby sea-level air pressure equivalent to be even coarsely accurate.