The Height of Skyscraper

The following concerns a question on 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. 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 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 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."

The arbiter accepted all answers and asked the student that you must be knowing what the professor was expecting?
The student replied,  yes I do,  but I hate others to decide what way I should think.

The student was Niels Bohr, the only Dane ever to win the Nobel Prize for Physics.!

LET THE MIND BE FREE

The Three Dolls

A sage presented a prince with a set of three small dolls. The prince was not amused.

“Am I a girl that you give me dolls?” – He asked.

“This is a gift for a future king,” Said the sage. “If you look carefully, you’ll see a hole in the ear of each doll.”


The sage handed him a piece of string. “Pass it through each doll.” – He said.

Intrigued, the prince picked up the first doll and put the string into the ear. It came out from the other ear. “This is one type of person,” said the sage, “whatever you tell him, comes out from the other ear. He doesn’t retain anything.”

The prince put the string into the second doll. It came out from the mouth. “This is the second type of person,” said the sage, “whatever you tell him, he tells everybody else.”

The prince picked up the third doll and repeated the process. The string did not come out. “This is the third type of person,” said the sage, “whatever you tell him is locked up within him. It never comes out.”

“What is the best type of person?” – Asked the prince.

The sage handed him a fourth doll, in answer. When the prince put the string into the doll, it came out from the other ear.

“Do it again.” – Said the sage.

The prince repeated the process. This time the string came out from the mouth. When he put the string in a third time, it did not come out at all.

“This is the best type of person,” said the sage. “To be trustworthy, a man must know when not to listen, when to remain silent and when to speak out.”

Always act according to the situation....
Have presence of mind....