ALEXANDER CALANDRA
( AN ARTICLE FM CURRENT SCIENCE TEACHER’S EDITION 1964)
SOMETIMES AGO , I RECEIVED A CALL FM MY COLLEAGUE WHO ASKED IF WUD B THE REFEREE ON GRADING OF AN EXAMINATION QUESTION. IT SEEMED THAT HE WAS ABOUT TO GIVE STUDENT A ZERO TO A PHYSICS QUESTION , WHILE THE STUDENT CLAIMED HE SHUD RECEIVE A PERFECT SCORE N WUD DO SO IF THE SYSTEM WERE NOT TO SET UP AGAINST THE STUDENT. THE INSTRUCTOR N THE STUDENT AGREED TO SUBMIT THIS IMPORTANT ARBITER N I WAS SELECTED.
THE BAROMETER PROBLEM……
i went to my colleague ’s office m read the examination question, which was” show how is it possible to determine the height of the tall building with the aid of barometer?’”
the students answer was” take the barometer to the top of the building , attach a apiece of rope to it, lower the barometer 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.”
Now , this is a very interesting answer, but shud the student get credit for it? i pointed out that the student realty had a strong case of full credit, since he had answered the question completely n correctly.on the other hand, if full credit were given, it cud well contribute to a high grade for the student in physics course. A high grade is supposed to certify that the student knows some physics, but the answer to the question didnt confirm this.with this in my mind , i suggested that the student hav another try at answering the question . i wasnt surprised that my coll;egue agreed to this, but i was surprised that the student did.
Acting in terms of agreement , i gave the student six minutes to answer the question, with the warning that the answere shud show some knowledge in physics . at the end of five minutes, he hadnt written anything . i asked if he wished top give up, since i had another class to take care of, but he said no, he wasnt giving up. he had many answers to the problem , n he was jus thinking of the best one. i excessed myself for interrupting him, and asked him to pls go on. in the next min, he dashed off his answer, which was,,,,,,,,,,,,,,,
” take the barometer to the top of the building n lean over the edge of the roof. drop the barometer , timing its fall with a stopwatch. then ,using the formula s= ut + 1/2at2, calculate the height of the building.”
At this point, i asked my colleague if he wud give up. he conceded n i gave the student almost full credit. ion leaving my colleague office , i recalled that the student had said he had other answers to the problem, so i asked him wat they were. “Oh yes,” said the student.”there r many ways of getting the height of the tall building with the aid of barometer . for example , u cud take the barometer out on a sunny day n measure the height of the barometer, the length of its shadow, and the length of the shadow of the building , and by simple proportion, determine the height of the building.”
“Fine,” i said . and the other’?
” YES, ” said the student .” there ris a very basic measurement method u will like . in this method , u take the barometer n begin to walk up the stairs . as u climb up the stairs , u mark off the length of the barometer along the wall.u then count the number of marks . and this will give u the height of the building in barometer units. a very direct method.
” of course , if u want more sophisticated method, u can tie the barometer to the end of string, swing it as a pendulum. fm the difference between two values of ‘g’ at the street level n at the top of the building. fm the difference between two values of’g', the height of the building can , in principle , be calculated.
Finally he concluded,” if u dont limit me to physics, solution to this problem, there r many other answers, such as taking the barometer to the basement n knocking on the superintendent ’s door. wen he answers, u speak to him as follows: ‘dear mr superintendent, here i have a very fine barometer, if u tell me the height of this building , i will give u this barometer.”
At this point, i asked the student if he really didnt know the answer to the problem. he admitted he did, but that he was so fed up with college instructors trying to teach him how to thinki n to use critical thinking , instead of showing him the structure of the subject matter , that he decided to take off on wat he regarded mostly as a sham…………………….
