Subject: Physics? > > > >The following concerns a question in a physics degree exam at the University >of Copenhagen : > > >'Describe how to determine the height of a skyscraper using 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. > >The student 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 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 sq root (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 Niels Bohr, the only person from Denmark to win the Nobel >prize for Physics > >__._,_.___ > > > > >__,_._,___
