利用聲頻偵測 APP、Tracker 與威力導演軟體 探究單擺運動的都卜勒效應

Abstract

此計畫所設計的物理實驗之主要器材有手機、Gopro 8 、無線藍芽耳機以及聲頻偵測APP、Tracker 和威力導演等免費軟體。因此非常適合學生於家中自行進行學習探討，也非常契合疫情期間的線上實驗教學目標。不僅如此，此計畫所進行的物理實驗主題並不常見於大學大一基礎物理實驗課，其特點包含 (1) 融合了單擺的牛頓力學和都卜勒效應的聲學現象; (2) 將教科書的線性都卜勒效應(亦即物體運動平行於音速方向)和非線性情況，進行實驗與理論的探討；(3) 將教科書之小角度單擺簡諧 運動延伸至大角度情況的實驗和理論分析； (4) 此實驗設計也納入 Matlab 程式撰寫及其在微分方程求解的應用。

According to our research, domestic colleges and universities in Taiwan rarely explored the Doppler effect of acoustic experiments in-depth in both freshmen and sophomore years. Especially the Doppler effect caused by a sound-emitting object when performing simple pendulum motion with a source velocity related to a stationary object. Therefore, in this experiment, we will use a string with one end tied with a Bluetooth earphone and the other end tied to a stand to perform pendulum motion. No special or expensive experimental equipment is needed to conduct this experiment. Experimental equipment we will be using includes two mobile phones, GoPro 8 (can be substituted by smartphone), one wireless Bluetooth earphone or an earbud, a 50cm cotton string, and an adjustable laboratory stand. Software and mobile phone APP will also be needed in this experiment including an audio detection APP (Physics Toolbox Suite), Tracker, and Power Director. In addition, due to the epidemic done by covid in the past two years, most of the experiment classes have been changed to online courses or canceled, which has a great impact on the experiment classes. Such a simple experimental design is suitable to be carried out at home, and the data collected can also be used to explore the Doppler effect of the pendulum motion.