Full Credit or A Zero?

Teacher gave a zero; student insisted on full credit!

I came across this story on a bulletin board of Columbia University. It was narrated by an MIT physics professor who was asked to mediate a grading dispute between a high school student and the teacher. The teacher had given the student zero on a particular question while the student insisted on getting full credit. The story made such an impression on my mind that I have never forgotten it. I do not have the exact narration. I am attempting to reconstruct the story from memory.

The question the student answered was: Using a barometer, how would you find the height of a tall building. The student answered that he would go to the top of the building, tie a string to the barometer and lower it till it touched the ground. He would mark the string, then pull up the barometer and then measure the length of the string to find the height of the building. The professor thought that technically the procedure would work although it was not the answer expected. He asked the student if he could attempt to answer the question a different way. The professor was a little surprised that the student readily agreed, and was then given 10 minutes to answer. The student sat in his chair thinking almost towards the end of time, without writing anything on the paper. The professor asked the student whether he was ready to give up or still intended to answer. The student said that actually he had several different answers and was trying to decide which one to write. The professor asked the student if he minded sharing all the “answers” he had. The student proceeded:

He said that one way he could determine the height of the building, was that he would drop the barometer from the top of the building and time with a stop watch the time it would took the barometer to hit the ground. Then he would use the equation of motion to calculate the height.

Another method he could use was to tap hard with the barometer and, if he could hear an echo from the ground, he could calculate the building’s height, knowing the speed of sound.

Yet another way was that on a sunny day he would measure the length of the building’s shadow and then hold the barometer vertical and measure its shadow. Then, by taking the ratio, he would be able to get the height.

Still another way would be to tie a string to the barometer and swing it as a pendulum and measure the time period to calculate the g-value at the bottom and top of the building. From that g-value difference, one should be able to derive the building’s height.

And, then there was, perhaps the easiest one -- that would require the least effort on his part. He would take the barometer to the building’s superintendent and tell him that he (the super) could have the nice barometer for free if he would tell him the height of the building.

The professor was impressed and amused by the student’s creative answers. Then he asked the student whether he knew that one could utilize barometer readings to find a building’s height. The student said that he, in fact, knew that but was sick of having to give only standard answers on exams.

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