On November 6th, Mr. Nelson YEUNG, the panel head of Physics, MSc. from The University of Hong Kong (HKU), introduced Grade 11 students to the fascinating world of sound waves using a cello. This hands-on experience not only brought theoretical concepts to life, but also inspired students to explore the science behind sound.

11月6日，东莞ASJ中学部物理科组负责人杨浩钧老师（香港大学硕士）巧妙地运用大提琴作为教学工具，为11年级选修物理的学生们揭开了声波世界的神秘面纱。这次实践不仅让抽象的理论概念变得更加生动，更激发了学生们探索声音科学奥秘的热情。

Exploring Sound Waves

探索声波

During the lesson, students delved into the nature of sound as a longitudinal wave. They learned that sound requires a medium, such as air, to travel, illustrating the importance of the environment in the transmission of sound. Mr. YEUNG discussed various phenomena associated with sound with the students, including reflection, refraction, diffraction, and interference. By conducting simple experiments, students observed how sound waves behave under different conditions, enhancing their understanding of these concepts.

在课堂上，学生们深入研究了声音的纵波性质。学生们了解到，声音需要通过介质（如空气）来传播，这凸显了环境在声音传播中的重要性。杨老师引导学生们探讨了声音的多种现象，包括反射、折射、绕射和干涉。通过简单的实验，学生们观察到声波在不同条件下的表现，从而增强了对这些概念的理解。

可听频率范围和超声波

The class explored the audible frequency range of human hearing, which is typically between 20 Hz and 20 kHz. Students were amazed to learn about ultrasound, which exists beyond this range and has various applications in medicine and technology. This discussion not only highlighted the significance of sound in diverse fields but also piqued the students' interest in further studies related to sound technologies.

师生们利用教室内的仪器，一起探索了人耳的可听频率范围，他们观察到人耳的可听频率范围通常在20 Hz到20 kHz之间。学生们对超声波的存在感到惊奇，这种波长超出可听范围的声波在医学和技术领域有着广泛的应用。杨老师还延展介绍了香港两间大学医学院采用的新型仪器，这种仪器可以利用超声波粉碎肝癌细胞，实现无辐射、无伤口的治疗，患者甚至可以即日出院。这一创新科技的应用不仅展示了声音在不同领域的重要性，也激发了学生们对声音技术研究的浓厚兴趣。

音乐音符：音高、音量和音质

Using the cello, students compared musical notes based on pitch, loudness, and quality. They engaged in hands-on activities where they experimented with different frequencies and amplitudes, directly relating these properties to the pitch and loudness of the notes produced. This experiential learning reinforced their theoretical knowledge and provided a tangible connection to the concepts discussed.

借助大提琴，学生们学习了如何根据音高、音量和音质来比较不同的音乐音符。在实践活动中，他们体验了不同频率和振幅的音效，并将这些物理特性与音符的实际音高和音量联系起来。这种体验式学习不仅巩固了他们的理论知识，也为抽象概念提供了具体的感知。

Understanding Noise Pollution

了解噪音污染

Mr. YEUNG also addressed the issue of noise pollution, discussing its effects on health and well-being. Students learned about sound intensity levels measured in decibels and the importance of acoustic protection. This part of the lesson sparked thoughtful discussions on how sound impacts our daily lives and the measures we can take to mitigate noise pollution.

杨老师还与学生们一起探讨了噪音污染问题，讨论了它对人体健康的影响。学生们学习了如何使用分贝来测量声音强度，并认识到了声音保护的重要性。这一课堂环节引发了对声音如何影响我们日常生活以及如何减少噪音污染的深入讨论。

Stationary Waves

驻波

Finally, the students investigated stationary waves, particularly in the context of transverse waves. Mr. YEUNG explained how stationary waves are formed and described their key characteristics. Students were able to visualize these concepts through demonstrations, further solidifying their understanding of wave behaviour.

最后，杨老师和学生们探讨了驻波，特别是在横波的背景下，解释了驻波的形成过程，并描述了其主要特征。学生们能够通过演示可视化这些概念，进一步巩固对波动行为的理解。