全國中小學科展

彭巴效應之實驗探討

科展類別

臺灣國際科展

屆次

2006年

科別

物理科

學校名稱

臺北市立金華國民中學

指導老師

林信忠、諶其騮

作者

丘雅鈺

關鍵字

彭巴效應,冷卻曲線

摘要或動機

延續38 屆北市科展的研究主題繼續研究,針對實驗方法進行改良。用熱敏電阻、數位電錶、冰箱冷凍庫、不同水溫,測繪「冷卻曲線」探討彭巴效應。發現在80℃、60℃、40℃、20℃的不同水初溫中,初溫愈高的水,完成冷涷的時間愈短。由冷卻曲線觀察,發現初溫較冷的水比熱水有更明顯的過冷現象。由冷卻曲線觀察,彭巴效應非常明顯,並且可由曲線上準確量測結冰始末的時間。彭巴效應明顯,並可重覆實驗。這次的研究探討,有助於我未來在彭巴效應實驗的量測技術。可應用於一般家庭冷卻物品時,快速冷卻,節省時間。可找出結冰的經濟初溫範圍,提供往後各領域利用. Hot water freezes faster than cold water? It is surprising to most people, but it is true. It has been observed and studied in numerous experiments. I tried to set up an experiment to explore the so-called Mpemba effect. I use NTC, multi-meter and house refrigerator to construct cooling curve for water of various initial temperature. The Mpemba effect is discussed based on the cooling curve. I found that the benefit of using NTC is faster measurement, higher sensitivity and cooling process is not disturbed. By inspection of the cooling curve, the Mpemba effect is obvious and repeatable. The initial and final state of freezing process is easily determined. Cold water reveals super-cooling phenomena. Inspection of gas bubbles in freeze ice showed that cold water contains more gas than hot water.

彭巴效應之實驗探討

Adobe Reader(Pdf)檔案