This lecture delves into classical applications of Bernoulli's equation, focusing on the measurement of speed in aircraft using pitot tubes and the principles behind venturi tube flow meters. The instructor explains how to calculate velocity using pressure differences and discusses the concept of mass conservation in fluid dynamics, illustrating its application in analyzing flow rates through pipes. Additionally, the lecture explores the dynamics of free jets and the relationship between velocity and height in a water jet. Throughout the lecture, the importance of choosing appropriate streamlines and making simplifying assumptions for accurate calculations is emphasized.