Miss Kate taught physics in a New York school. Last month she was explaining to one of her classes about sound, and she decided to test them to see how well they had understood her explanation. She said to them, “Now, I have a brother in Los Angeles. If I was calling him on the phone, and at the same time you were 80 meters away, and were listening to me from across
the street, which of you would hear what I said earlier, my brother or you and for what reason?”
A boy at once answered, “ Your brother, Miss Kate, because electricity travels faster than sound waves(声波).
“That’s very good.” Miss Kate said, but then Jenny said, “I don’t agree. Your brother would hear you earlier because it is 11 o’clock here, it’s only eight o’clock in Los Angeles.”
Miss Kate was a physics teacher.
All her students understood her lesson.
The boy’s answer was not correct.
The boy’s answer was just what Kate wanted her students to know.
Jenny thought the boy’s reason was wrong because she found Los Angeles Time was three hours earlier than New York Time.