Engaging undergraduates in active learning is critical for advancing their scientific literacy, which plays increasingly bigger role in modern society. Introductory Physics-101 is one of our best platforms to achieve this goal. Yet because it examines fast-speed phenomena which cannot be seen by the naked eye (e.g. acoustic vibrations), keeping the students engaged is challenging. We have developed an advanced in-class demonstration technology, based on a high-speed camera, for in-class demonstrations of fast phenomena that are impossible to visualize and analyse otherwise. In this talk, we will discuss the details of our approach and the results of its recent implementation.