Fail this question you should give up trading
- Thread starter WallstYouth
- Start date
Quote from Quiet1:
ok i had that one at interview too (but for me it was two men and a dog)....
how about this one: i have two ropes and a lighter. i know if i light the end of each rope they will burn for exactly 1 hour. use the ropes to measure exactly 45 mins.
Q1
I can't believe noone has answered this one yet ..
"assumuing" the rope burns consistently, then you light one rop at one end and at the same time light the other rop at both ends. When the second rope finishes burning you have 30 mins left on the first rope ... so just light the other end of the remaining rope for an extra 15 mins ...
Sir Ernest Rutherford, President of the Royal Academy, and recipient of the Nobel Prize in
Physics, related the following story:
Some time ago I received a call from a colleague. He was about to give a student a zero
for his answer to a physics question, while the student claimed a perfect score. The
instructor and the student agreed to an impartial arbiter, and I was selected. I read the
examination question:
"Show how it is possible to determine the height of a tall building with the aid of a
barometer."
The student had answered: "Take the barometer to the top of the building, attach a long
rope to it, lower it to the street, and then bring it up, measuring the length of the rope.
The length of the rope is the height of the building."
The student really had a strong case for full credit since he had really answered the
question completely and correctly! On the other hand, if full credit were given, it could well
contribute to a high grade in his physics course and certify competence in physics, but the
answer did not confirm this.
I suggested that the student have another try. I gave the student six minutes to answer the
question with the warning that the answer should show some knowledge of physics. At the
end of five minutes, he hadn't written anything. I asked if he wished to give up, but he said
he had many answers to this problem; he was just thinking of the best one. I excused
myself for interrupting him and asked him to please go on. In the next minute, he dashed
off his answer, which read:
"Take the barometer to the top of the building and lean over the edge of the roof. Drop the
barometer, timing its fall with a stopwatch. Then, using the formula x=0.5*a*t^2,
calculate the height of the building."
At this point, I asked my colleague if he would give up. He conceded, and gave the student
almost full credit. While leaving my colleague's office, I recalled that the student had said
that he had other answers to the problem, so I asked him what they were.
"Well," said the student, "there are many ways of getting the height of a tall building with
the aid of a barometer. For example, you could take the barometer out on a sunny day and
measure the height of the barometer, the length of its shadow, and the length of the
shadow of the building, and by the use of simple proportion, determine the height of the
building."
"Fine," I said, "and others?"
"Yes," said the student, "there is a very basic measurement method you will like. In this
method, you take the barometer and begin to walk up the stairs. As you climb the stairs,
you mark off the length of the barometer along the wall. You then count the number of
marks, and this will give you the height of the building in barometer units. A very direct
method.
"Of course."
"If you want a more sophisticated method, you can tie the barometer to the end of a
string, swing it as a pendulum, and determine the value of g [gravity] at the street level
and at the top of the building. From the difference between the two values of g, the height
of the building, in principle, can be calculated."
"On this same tack, you could take the barometer to the top of the building, attach a long rope to it, lower it to just above the street, and then swing it as a pendulum. You could then calculate the height of the building by the period of the precession".
"Finally," he concluded, "there are many other ways of solving the problem. Probably the best," he said, "is to take the barometer to the basement and knock on the superintendent's door. When the superintendent answers, you speak to him as follows: 'Mr. Superintendent, here is a fine barometer. If you will tell me the height of the building, I will give you this barometer.'"
At this point, I asked the student if he really did not know the conventional answer to this
question. He admitted that he did, but said that he was fed up with high school and college
instructors trying to teach him how to think.
The name of the student was Niels Bohr (1885-1962); Danish Physicist; Nobel Prize 1922;
best known for proposing the first "model" of the atom with protons and neutrons, and
various energy states of the surrounding electrons -- the familiar icon of the small nucleus
circled by three elliptical orbits... but more significantly, an innovator in Quantum Theory.
Physics, related the following story:
Some time ago I received a call from a colleague. He was about to give a student a zero
for his answer to a physics question, while the student claimed a perfect score. The
instructor and the student agreed to an impartial arbiter, and I was selected. I read the
examination question:
"Show how it is possible to determine the height of a tall building with the aid of a
barometer."
The student had answered: "Take the barometer to the top of the building, attach a long
rope to it, lower it to the street, and then bring it up, measuring the length of the rope.
The length of the rope is the height of the building."
The student really had a strong case for full credit since he had really answered the
question completely and correctly! On the other hand, if full credit were given, it could well
contribute to a high grade in his physics course and certify competence in physics, but the
answer did not confirm this.
I suggested that the student have another try. I gave the student six minutes to answer the
question with the warning that the answer should show some knowledge of physics. At the
end of five minutes, he hadn't written anything. I asked if he wished to give up, but he said
he had many answers to this problem; he was just thinking of the best one. I excused
myself for interrupting him and asked him to please go on. In the next minute, he dashed
off his answer, which read:
"Take the barometer to the top of the building and lean over the edge of the roof. Drop the
barometer, timing its fall with a stopwatch. Then, using the formula x=0.5*a*t^2,
calculate the height of the building."
At this point, I asked my colleague if he would give up. He conceded, and gave the student
almost full credit. While leaving my colleague's office, I recalled that the student had said
that he had other answers to the problem, so I asked him what they were.
"Well," said the student, "there are many ways of getting the height of a tall building with
the aid of a barometer. For example, you could take the barometer out on a sunny day and
measure the height of the barometer, the length of its shadow, and the length of the
shadow of the building, and by the use of simple proportion, determine the height of the
building."
"Fine," I said, "and others?"
"Yes," said the student, "there is a very basic measurement method you will like. In this
method, you take the barometer and begin to walk up the stairs. As you climb the stairs,
you mark off the length of the barometer along the wall. You then count the number of
marks, and this will give you the height of the building in barometer units. A very direct
method.
"Of course."
"If you want a more sophisticated method, you can tie the barometer to the end of a
string, swing it as a pendulum, and determine the value of g [gravity] at the street level
and at the top of the building. From the difference between the two values of g, the height
of the building, in principle, can be calculated."
"On this same tack, you could take the barometer to the top of the building, attach a long rope to it, lower it to just above the street, and then swing it as a pendulum. You could then calculate the height of the building by the period of the precession".
"Finally," he concluded, "there are many other ways of solving the problem. Probably the best," he said, "is to take the barometer to the basement and knock on the superintendent's door. When the superintendent answers, you speak to him as follows: 'Mr. Superintendent, here is a fine barometer. If you will tell me the height of the building, I will give you this barometer.'"
At this point, I asked the student if he really did not know the conventional answer to this
question. He admitted that he did, but said that he was fed up with high school and college
instructors trying to teach him how to think.
The name of the student was Niels Bohr (1885-1962); Danish Physicist; Nobel Prize 1922;
best known for proposing the first "model" of the atom with protons and neutrons, and
various energy states of the surrounding electrons -- the familiar icon of the small nucleus
circled by three elliptical orbits... but more significantly, an innovator in Quantum Theory.
Thanks for helping me start the day with a smile!
Well "Wall St Youth", your inane question seems to have puzzled most everyone here. I think the notion of a 60 mph bird kind of blew all of our minds. Personally, I was so gripped with fear at the thought of a 60mph flying bird, that I could not take the question seriously.
I'm guessing you are the Einstein who created this question.
I'm guessing you are the Einstein who created this question.