I laughed and pointed out to my colleague that we must admit that the student really had a pretty strong case for full credit since he had indeed answered the question completely and correctly. On the other hand, I could also see the dilemma because if full credit were given to him it could mean a high grade for the student in his physics course. A high grade is supposed to prove competence in the course, but the answer he gave did not show his knowledge on the subject. "So, what would you do if you were me?" Jim asked. I suggested that the student have another try at answering the question. I was not surprised that my colleague agreed, but I was surprised that the student did, too.
I told the student that I would give him six minutes to answer the question. But I warned him that this time his answer should show some knowledge of physics. He sat down and picked up his pen. He appeared to be thinking hard. At the end of 5 minutes, however, I noticed that he had not put down a single word. I asked him if he wished to give up, but he said no. He had not written anything down because he had too many possible answers to this problem. He was just trying to decide which would be the best one.